Now only the highest-density rubble fields block sight
Being in a vehicle will make a PC/NPC impervious to being hit by rubble
Fixing minor debugmsg typo
Biasing rubble spawning away from the most dense piles
Fixing logic error in rubble spawning bias
Adding floor rubble-spawning changes to wall rubble-spawning
Now only vehicle roofs will protect vehicle-bound (N)PCs.
Implemented more robust vehicle rubble protection for (N)PCs
Merging changes from the main cavein branch