JED 1.6.0 configuration and command changes

- JED configuration and command changes in 1.6.0:

  * Changed or moved config keys:
      - disableteleportingfrom    => disable_teleporting_from
      - disableteleportingto      => disable_teleporting_to
      - vanilladimensiontype      => existing_dimensiontype
      - worldinfo.JED             => jed
      - colors                    => jed.Colors
      - JED.ForceGamemode         => jed.ForceGameMode

  * Changed commands:
      - unloademptydimensions     => unload-empty-dimensions
      - listloadeddimensions      => list-loaded-dimensions
      - listregisteddimensions    => list-registed-dimensions
      - reloadmainconfig          => reload-main-config

  * Changed command args:
      - unloademptydimensions argument 1: true => unload-chunks

  * Other changes:
    - Starting from build 1.6.0-dev.20171225.032648, JED tries to re-use existing DimensionType entries as much as possible.
      * There are three new config options to control that, and they all go inside the `dimensiontype` object in the config:
        - forge_register: [true | false] - Forces a registration of a new entry. This is false by default, and usually not recommended.
        - allow_different_id: [true | false] - Controls whether or not an entry with a different DimensionType ID can be used. This is true by default.
        - require_exact_match: [true | false] - Controls whether or not an entry with any different properties (unimportant ones, such as the name) can be used. This is false by default. Set this to true if you want to register a dimension with a specific name (basically if it's visible somewhere in-game).
    - An empty string given for the RandomSeed value (ie. `"RandomSeed": ""`) in a worldinfo section now generates a new random seed for that dimension when it's loaded for the first time
    - When providing the SpawnX and SpawnZ coordinates without a SpawnY coordinate inside a worldinfo section, JED will try to find the top block in that XZ-column

  * Added commands:
      - /jed load-dimension <dimId>
      - /jed delete-dimension <dimId> [confirm]
        * This command requires a confirmation to avoid accidental deletions. Run it first without the 'confirm' argument, and then again with it.

  * Added other features:
      - Added a "DummyRenderer" which can be used as the sky, cloud or weather renderer to essentially disable that rendering
      - Added a 'ChunkGeneratorFlatJED' custom flat world generator, which supports caves ('caves' in generatorOptions), and disabling modded population ('no_mod_population' in generatorOptions)

  * Added "top level" configs (these go directly inside the dimension's object in the config, not nested inside dimensiontype or worldinfo*):
      - biomeprovider (string): Forces a specific BiomeProvider to be created by class name. Note that only one constructor format is supported (with a WorldInfo argument), so modded providers may not work if they require other arguments.
      - chunkgenerator (string): Selects the ChunkGenerator to use in a dimension (requires a JED WorldProvider, and only supports a fixed number of constructor argument formats).
        > Can be 'ChunkGeneratorFlatJED', or otherwise a fully qualified class name of a ChunkGenerator.
        > The vanilla generator names are: 'net.minecraft.world.gen.ChunkGeneratorOverworld', 'net.minecraft.world.gen.ChunkGeneratorHell', 'net.minecraft.world.gen.ChunkGeneratorEnd', 'net.minecraft.world.gen.ChunkGeneratorFlat'.
      - load_on_start (boolean): If true, causes the dimension to get registered a bit earlier than they would otherwise, causing the dimension to get loaded on server start due to how vanilla/Forge works.
      - normal_biomes (boolean): If true, then the BiomeProvider will be overridden with the vanilla default overworld BiomeProvider
      - post_deletion_command (string): A command that will be run after a temporary dimension gets deleted. (for example a say or broadcast command to inform the player)
      - spawn_structure (object): Place the given structure at the dimension/world spawn when the dimension is first created. File goes in config/justenoughdimensions/structures/<name>.[schematic|nbt]
        * Example:
          "spawn_structure": {
              "name": "stargate.schematic",
              "rotation": "<none | cw_90 | cw_180 | ccw_90>",
              "mirror": "<none | left_right | front_back>",
              "centered": true,
              "offset": [0, -2, 0],
              "load_around": 16
          }
        * The 'load_around' value is the number of extra blocks (rounded up to chunks) to load around the structure before placing it
        * All values except 'name' are optional. Rotation and mirror default to none, centered defaults to false, offset to [0, 0, 0] and load_around to 16 blocks.
      - temporary_dimension (boolean): If true, then the dimension in question (or the entire world if set for dimension 0), will get deleted when it unloads and no players are in that dimension
      - world_template (string): If set, then on first load of the dimension, a template world is copied from config/justenoughdimensions/world_templates/<name>

  * Added "JED" configs:
      - jed.AverageGroundLevel (int)
      - jed.CanDoLightning (boolean) - enable/disable lightning (and skeleton trap horses)
      - jed.CanDoRainSnowIce (boolean) - enable/disable water freezing, plus snowing and blocks filling with water while raining
          (the snowing and filling with water also depend on HasSkyLight for weather/rain to happen in the first place)
      - jed.CanSleepHere (string) - one of 'allow', 'deny', 'bed_explodes'
      - jed.CanSpawnHostiles (boolean) - override the normal difficulty-based behaviour
      - jed.CanSpawnPeacefulMobs (boolean) - override the normal value, which is true in hardcore mode and single player, and on servers it's the 'spawn-animals' in server.properties
      - jed.CelestialAngleMin (float, 0.0 - 1.0) - Use a customized celestial angle range (needs both min and max set to take effect)
      - jed.CelestialAngleMax (float, 0.0 - 1.0) - Use a customized celestial angle range (needs both min and max set to take effect)
      - jed.ChunkGenFactoryWorldProvider (string) - A temporary World Provider override during dimension load, just used to create a ChunkGenerator from a mod, that will then be used with some other World Provider later on
      - jed.CloudRenderer - The fully qualified class name of a custom cloud renderer
      - jed.DayTimeMin (int, 0 - 23999) - Use a customized world time range. This may work weirdly with things... (needs both min and max set to take effect)
      - jed.DayTimeMax (int, 0 - 23999) - Use a customized world time range. This may work weirdly with things... (needs both min and max set to take effect)
      - jed.DayCycleIncrement (int, default = 24000) - The amount of ticks the world time is incremented per day cycle when using the DayTimeMin & DayTimeMax options.
      - jed.DisableDawnDuskColors (boolean) - Disables the sunrise and sunset sky/fog coloring at the horizon
      - jed.DisableEnderDragon (boolean) - Overrides the DragonFightManager with a dummy one, disabling the Dragon related stuff (needs WorldProviderEndJED)
      - jed.DisableEndSpikes (boolean) - Uses ChunkGeneratorEndJED, which disables the End Spike (obsidian towers) generation (needs WorldProviderEndJED)
      - jed.DontAdvanceWeatherWhenSleeping (boolean) - Prevents clearing the weather when players sleep to pass the night
      - jed.FoggyBiomes (object) - define which biomes either have or don't have fog
          * A "listed_have_fog" boolean value controls whether the list is a "whitelist" or "blacklist" for foggy biomes
          * Example:
              "FoggyBiomes": {
                  "listed_have_fog": true,
                  "biomes": [
                      "minecraft:swamp",
                      "minecraft:roofed_forest"
                  ]
              }
      - jed.GenerateFallbackSpawnBlock (boolean) - If true, and the spawn position JED found is in mid-air (void dimensions), then a glass block will be placed right under the spawn
      - jed.HasSkyLight (boolean) - Affects things like weather and light calculations
      - jed.HasXZFog (boolean) - Fog will be rendered around the player
      - jed.Horizon (double) - the height of the horizon (used for sky rendering)
      - jed.IgnoreSpawnSuitability (boolean) - If true, doesn't check the biome's spawn suitability or try to search for a grass block to spawn on
      - jed.IsSurfaceWorld (boolean) - compass & clock models, enables cloud & sky rendering, enables (vanilla) sleeping, pigmen spawn from portals
      - jed.MovementFactor (double) - the portal scaling factor
      - jed.MusicType (string) - The ambient music type that should be used in this dimension
      - jed.ShouldClientCheckLight (boolean) - Whether the client should check/re-calculate the light data in the received chunks
      - jed.SkyLightBlend (double) - Allows controlling the sky color blending with the light level, allowing to have a colored sky at night too. Range: 0.0 - 1.0, default = 1.0 (normal light blending).
      - jed.SkyRenderer - The fully qualified class name of a custom sky renderer
          for example to use the GoG sky box: "SkyRenderer": "vazkii.botania.client.render.world.SkyblockSkyRenderer"
      - jed.SpawnPointSearchType (object) - allows customizing the spawn point search code behaviour, and the algorithm to use for it
        * Has the following values:
          - type (string) - one of 'overworld', 'cavern' or 'none'. The cavern type is used for Nether dimensions by default. 'none' skips the spawn point search for that dimension.
          - min_y (int) - the lowest y-coordinate to search in
          - max_y (int) - the highest y-coordinate to search in
        * The search algorithm starts from the max_y value at each XZ-column and goes down to the min_y value
        * The min_y and max_y values are optional, and they will override the internal default values, which depend on the algorithm type
        * Example: https://pastebin.com/MW16pnVn
      - jed.SunBrightnessFactor (float) - ?
      - jed.SunBrightness (float) - ?
      - jed.VoidTeleportInterval (integer) - The interval in ticks how often entities are checked if they need to be teleported from the void or the sky. Default is 40 ticks (2 seconds).
      - jed.WaterVaporizes (boolean) - Overrides whether or not water should vaporize (on bucket use and ice melting, like in the nether)
      - jed.WeatherRenderer (string) - The fully qualified class name of a custom weather renderer
      - jed.WorldBorderCenteredOnSpawn (boolean) - If true, and the dimension is using WorldInfo overrides/values, then the World Border will be centered to the spawn point
      - jed.WorldProviderOverride (string) - "manually" override the WorldProvider, without using a custom DimensionType entry with the correct provider
      - jed.sky_teleport (object) - The options to control how sky teleporting works in this dimension
      - jed.void_teleport (object) - The options to control how void teleporting works in this dimension
          "<sky | void>_teleport": {
              "dimension": 10,
              "trigger_y": -10,
              "find_surface": <true | false>,
              "remove_fall_damage": <true | false>,
              "fall_distance": 4.5, // if "remove_fall_damage" doesn't exist, but this key/value does, then this value will be used as the fall distance
              "min_health_left": 1, // if this value exists, then the maximum fall damage/distance will be limited such that this amount of health will remain
              "teleport_type": "<same_location | fixed_location | spawn | scaled_location | relative_location | scaled_relative_location>",
              "scale": [8, 1, 8],
              "fixed_location": [256, 64, 256],
              "relative_location": "~ 256 ~+32"
          }
          - Note: The 'offset_location' type and the 'offset' value were removed as of the 2020-04-16 build, as it was redundant and just a more limited variant of the relative_location type
          - The 'scaled_relative_location' type was added on 2020-04-16, and it uses the 'scale' value first, and then applies the 'relative_location' on top of the scaled location
          - Example 1:
          "jed": {
              "...": "...",
              "void_teleport": {
                  "dimension": 10,
                  "trigger_y": -10,
                  "find_surface": true,
                  "remove_fall_damage": true,
                  "teleport_type": "scaled_location",
                  "scale": [8, 1, 8]
              }
          }
          - Example 2:
          "jed": {
              "...": "...",
              "void_teleport": {
                  "dimension": -1,
                  "trigger_y": -4,
                  "remove_fall_damage": true,
                  "teleport_type": "scaled_relative_location",
                  "scale": [8, 1, 8],
                  "relative_location": "~ 128 ~+48"
              }
          }