CDDA Trailer Park Mod

Adds trailer parks to map generation, as well as regular and small trailers.

Everything works? Everything works

• might play a little with the items that get spawned in the RVs
• does it spawn on the map enough? too much? i dunno
• the monsters that spawn there probably need balancing
• is that wall type okay for the shelter? i don't know if i like it
• things should spawn in the dumpsters, but they don't yet
• another version of the park with bandit fortifications and glass pits and stuff
• how to basement? make one down from the shelter? it's a storage area? question mark?
• bandits totally use the storage area for a makeshift prison