Fix map loading. Fix gravity. Add functionality to entities. Add util support.

Firstly, map loading (where it was strangely loading with columns and rows switched)
is fixed. Also, gravity is now capped as to prevent entities from embedding themselves
into the ground during long falls. Gravity also has been changed so that entities land flatly
on surfaces (and render as such.) Entities can have their centerpoint gotten much in the 
way that origin points can. The GameLauncher class supports command line arguments
to load development tools (with a WIP MapViewer)