Document setup work.
Remove GL_FOG_DENSITY, which is unused when using the GL_LINEAR fog mode.
Document motion and line of sight calculations.
Turn magic movement numbers into constants and compute jump speed instead of hard-coding it.
Pull out ticks per second into a constant.
Document collision detection.
Make adding blocks work on OSX.
Merge pull request #43 from jesstess/jesstess

Add some documentation and make adding blocks work on OSX