Building implementation evaluation

This proposal explores how (smaller) buildings should be implemented in PARPG.

Infinity Engine approach
The interior of buildings resides at separate maps.

Fallout approach
The interior of (smaller) buildings is part of the outdoor map.

Pros

 * You can shoot into and out of houses

Cons

 * Walls have to be split up into smaller pieces to avoid z-ordering issues
 * Complex graphics department asset pipeline required