LevelEditor objects will be stored in a grid

-Objects can't be placed in each other if snap to grid is on
-Objects need special description in BlockInfo.txt
-Updated to 4.6.1
Pre-defined object extents apply to grid
Exit button for LevelEditor
Removed snap input
New file parser
Fixed object y-offset
Basic LevelEditor testing
Testing improvements

Still TODO:
-Start countdown doesn't work
-Respawning doesn't work
-Race time doesn't work
Better positioning of debug window