Modding:
    - Ambient sounds are specified as prototypes so they can be extended and modified by mods.
  Scripting:
    - Changed all the identifiers/methods/events/parameters. Underscores are used as word delimiter (findentities -> find_entities).
    - Changed glob to global.
    - New object LuaSurface, accessible from player/entity as read property surface.
    - Some commands moved from LuaGame to LuaSurface: get_pollution, can_place_entity, find_entity, find_entities, find_entities_filtered,
      find_non_colliding_position, find_enemy_units, find_nearest_enemy, set_multi_command, create_entity, create_unit_group, build_enemy_base,
      get_tile, get_tileproperties, set_tiles, pollute, get_chunks, is_chunk_generated
    - Added LuaFluidPrototype - similar to LuaItemPrototype but for fluids.
    - math.random can now accept negative values for ranges eg x + math.random(-10, 10)
    - Added LuaRecipe::hidden and energy read.
    - New object LuaGroup, accessible from LuaEntityPrototype as read property group/subgroup.
      LuaGroup contains: name, type, inventory_order, group, subgroups
    - Added several new options to LuaEntityPrototype: mineable_properties, items_to_place_this, collision_box, selection_box, order,
      group, subgroup, healing_per_tick, emissions_per_tick, corpses, selectable_in_game, weight, resistances, fast_replaceable_group,
      loot, repair_speed_modifier
    - LuaItemPrototype::group now returns the new LuaGroup object.
    - Added LuaEntity::is_crafting() - returns true/false if the assembling machine or furnace is currently crafting a recipe.
    - Added LuaEntity::crafting_progress/bonus_progress - a percent of 1: the current crafting progress or bonus progress.
    - Added the ability to compare LuaObjects using "==" as in: "if game.player == game.players[1]" for all LuaObjects.
    - Removed all LuaObject::equals(): the == operator can be used in its place.
    - Added new blend modes for sprites using "blend_mode" property. Possible values: "normal", "additive", "multiplicative".
    - Added on_player_driving_changed_state event - passes the player_index who's driving state changed.
    - Added LuaEntity::belt_to_ground_type - returns the type "input"/"output" of the transport-belt-to-ground.
    - Added several methods for manipulating gates: is_opened, is_opening, is_closed, is_closing, request_to_open, request_to_close.
    - Changed LuaEntity::neighbours:
      For electric poles: the wire connections: {copper={}, red={}, green={}}
      For transport-belt-to-ground: the input/output entity it's connected to (or none)
      For entities with fluid - the entities the fluid connections connect to indexed by the fluid connection
    - #entity.fluidbox can now be read from any entity and will return the number of fluidboxes the entity has (0 for non-fluid handling entities).
    - Added the ability to specify map colors for all entities: map_color, friendly_map_color, and enemy_map_color
    - Added the ability to disable drawing the station name for train-stop type entities: chart_name = "false" in the prototype.
    - LuaEntity::backer_name can now be read/written for all entities that support backer names (furnace, assembling machine, lab, locomotive, radar, roboport, trainstop).
    - LuaEntity::recipe can now be set to nil to remove the recipe from an assembling machine.
    - Added LuaItemPrototype default_request_amount, resistances, item_to_clear.
    - Added LuaChart::chart_all (charts all the generated parts of the map).
    - Expanded LuaEntity::get_item_count and LuaEntity::clear to work with all transport belt entities.
    - New object LuaTransportLine, accessible from entity as read method get_transport_line(index) - an interface to the items on transport belts.
    - Added LuaSurface::count_entities_filtered - the same as find_entities_filtered but simply returns a count. The benefits being: it's much faster
      than find_entities_filtered when the entity references aren't desired.
    - Added LuaForce::enable_research() - enables research for the force if it was disabled.
    - Added LuaSurface::spill_item_stack() - takes a item_stack and position and drops the items on the ground item bomb style.
    - Changed LuaEntity::stack, LuaEntity::held_stack and LuaPlayer::cursor_stack to return LuaItemStack objects.
    - Changed LuaItemStack to allow reading any inventory slot even when the item in the slot is invalid. LuaItemStack::valid_for_read should be used
      before accessing the normal properties/methods for a given LuaItemStack.
    - Removed LuaEntity::clear_circuit_condition() - LuaEntity::set_circuit_condition(index, nil) can be used instead.
    - Added "force" option to LuaSurface::find_entities_filtered/count_entities_filtered.
    - ItemStack counts can be excluded and defaults to 1, ItemStacks can be strings and default to a full stack.
    - Added LuaItemStack::count write support.
    - Added LuaItemStack::can_set_stack(), set_stack(), clear() - write support to a specific item stack.
    - Removed LuaEntity::stack, held_stack write support - LuaItemStack::set_stack() can be used.
    - Removed LuaPlayer::cursor_stack write support - LuaItemStack::set_stack() can be used.
    - Added LuaTrain::cargo_wagons read - returns only the cargo wagons for the given train.
    - Added LuaEntity::remove_market_item - takes an index to remove from a Market entity offer list.
    - Added LuaEntity::get_market_items - returns a table of offers the Market entity offers.
    - Added LuaForce::research_progress read/write - a percent of 1 - the current research progress (0 if no research).
    - Added LuaEntityPrototype::turret_range read - the range of a given turret entity prototype.
    - Added player_index to the on_put_item event.
    - Added ghosts from manual building and blueprints to the on_built_entity event.
    - Added LuaPlayer::enable_flashlight() - counterpart to disable_flashlight().
    - Replaced LuaGameScript::kill_all_enemies() by LuaForce::kill_all_units().
    - Changed on_researched events to return the relaed LuaTechnology object.
    - Added LuaTechnology::force read - the LuaForce the technology belongs to.
    - Added LuaGame::create_surface - takes a string name and optionally a table of map gen settings and creates a new surface.
    - Changed LuaPlayer::teleport to allow optionally a surface name, index or object to teleport the player to. The surface must exist.
    - Added LuaSurface::request_to_generate_chunks - takes a position and radius and requests to generate those chunks - will not generate chunks outside the map bounds.
    - Added LuaSurface::map_gen_settings - the current map gen settings for the surface.