FINALLY fixed the bug with fillInSpaces().  Turns out
[[False]*C.MAP_HEIGHT]*C.MAP_WIDTH is not a good way to initialize a
list of lists.
Added some precautionary commit calls to some database methods.
Cleaned up imports in LevelClass.py
Added blankBackground
Commented out blankBackground: not actually a Color object
Implemented DungeonFeature class and its first subclass, Door
Implemented random door placement on vertical and horizontal tunnels.
Added a method to build up tileArray now that I know how to do that
right.
Wrote getRandomTile and getRandomOpenTile methods
Changed getSpacesInRadius and getSpacesAtRadius => getTiles*Radius, and
implemented.
Added upStair and downStair to DungeonFeatureClass.py
Implemented getRandomTileInArea and getRandomOpenTileInArea
Implemented stair placement in level creation
Implemented stair placement.  Need to work on the relationship config
for Tile and DungeonFeature though
Fixed relationship specification from Tile to Stair objects.
Added drawSpace, drawTile, and computeFOVProperties() methods to
Level class
FOV working!
Some bug fixing.  Reworked Level.computeFOVProperties() so that it's
faster.
Removed unneeded FOVMapClass.py
A bit of cleanup