Add animal and food; redo voxel reference so there's not extra allocs.
Load png images too; if not png, try bmp.
images get loaded ARGB not BGRA; modify load texture settings.
Move defintiion of gcc compiler intrinsic; make it an exception for known cases instead of unknown cases.
Move specific define for swap_and_compare gcc(and many other) macro...
change to a test for known exception cases instead of default for unknown cases.
Merge branch 'back-propagation'