Reorganize Makefile build into a more modular scheme.
Cleanup of RegalDispatchTraceExclude.py for better clarity / TODO purposes.
Consolidation of environment variable queries at runtime.
ARB_texture_cube_map and EXT_texture_cube_map for ES 2.0
IFF emulation improvements
Emscripten build improvements
Update zlib to version 1.2.8
Update libpng to version 1.6.3
Update mongoose to version 3.8
Merge remote-tracking branch 'github/master' into cass