Fix warnings
Build and run tests on NaCl
Merge branch 'test_on_nacl' of https://github.com/sbc100/regal
Add enums for GL_HP_image_transform
Add enums for GL_SGIX_fragment_specular_lighting
Runtime flag for thread locking - work in progress
Platform notes for NaCl builds
Disable extra logging diagnostics for REGAL_SYS_PPAPI=1, for performance reasons
Refresh GLEW with DSA workaround - ignore fp64 stuff.
Add Mesa3D to the lists of known OpenGL implementations for Linux GLX.
For GLUT on Windows, simple ASCII to UCS2 unicode conversion for SetWindowText.
For DSA emulation layer, use Regal::DispatchTable::call rather than calling back into the emulation layer directly.  For github issue #65.

https://github.com/p3/regal/issues/65
Initial multi-threading for global context mappings
Initial implementation of Iff::Cleanup for claiming back GL resources, if possible.
Merge remote-tracking branch 'upstream/master'