cp2 unit spawning mandatory

Ideen für Verbesserungen am Unit Skript:
- Units spawn at their respective buildings. If multiple spawning locations exist for a unit type, one is selected at random.
- If all corresponding unit type production structures are dead, this unit type can no longer be purchased by that evil base.
  Which unit type corresponds to which structure(s) is set globally for streamlined/logical user experience.
- Stagger unit spawn at custom interval, defaults to .05 seconds.
- Units will automatically attack-move to a certain point. Defaults to CP Base spawning area/main building.
- Unit type spending can be set to frequency mode. Spend 1 of the most expensive unit, then go down up until the cheapest unit. If resources are still remaining, spawn cheapest unit again and go back up. If resources still exist when reaching the most expensive unit, spawn the most expensive unit a 3rd time. If resources are still there, go random where the first random unit can not be the most expensive one.
- Separate function for a manual purchase, ignoring the timer and providing a custom money amount. One time spawn with the base's set behaviour and unit types. Timer, money and other settings are not touched by a call to this function.