* Python >= 2.5
* Pyglet
* Rabbyt
* Numpy

`$ python -O snowball.py` will strip out all profiling (a LOT of function calls).

use `debug` and `play` to get profiling and quick play on the command line respectively.

Map Creation
* terrain.png - greyscale image; pixels -> tiles; white high, black low.
* static_map_objects.png - RGBA image with the same size as terrain.png
* buildings.txt, dynamic_objects.txt, paths.txt, script.sbs, script_areas.txt
  and settings.json must exist.

Known Bugs

* Errors like this will appear randomly and crash the game when using pyglet 1.1.3
  Use pyglet 1.1.2 until pyglet 1.1.4 is released.
  File "/home/joey/projects/games/snowballz/lib/scene.py", line 33, in loop
  File "build/bdist.linux-x86_64/egg/pyglet/clock.py", line 317, in tick
  File "build/bdist.linux-x86_64/egg/pyglet/clock.py", line 585, in _get_soft_next_ts
  File "build/bdist.linux-x86_64/egg/pyglet/clock.py", line 563, in taken
TypeError: unsupported operand type(s) for -: 'NoneType' and 'float'