Merge branch nacl_updates of https://github.com/sbc100/regal
Move zlib, libpng, GLU and GLUT source lists into build/foo.inc for Makefile build.
Move NACL_SDK_ROOT logic into config/Makefile.nacl
Makefile revamp - put libs in lib/$(SYSTEM) and binaries in bin/$(SYSTEM)
Add clobber target for wiping out all temps, libs and binaries
Fixups for core and compat profiles.
Fix texture issue on pepper platform.