Further reduce number of calls to map::ter() by caching the value and referencing it multiple times in build_outside_cache().
Recuce calls to map::ter() a little more by stashing the value locally.
Merge branch 'master' of github.com:TheDarklingWolf/Cataclysm-DDA into for-darklingwolf
Replace open-coded is_outside() with simple loop.
Merge git://github.com/kevingranade/Cataclysm
Add a FAQ for devs and an initial post explaining relationships between map classes.
Merge pull request #22 from zpmorgan/master

fix for #21: segfault on going downstairs
Merge branch 'master' of https://github.com/TheDarklingWolf/Cataclysm-DDA
Merge branch 'master' of github.com:TheDarklingWolf/Cataclysm-DDA into for-darklingwolf
little optimization.

I noticed a bunch of wolves checking for lit torches too often.