Initial scaffolding for GLX emulation on EGL/WGL/CGL.
Ppca refinements.
Add GL_NV_blend_equation_advanced and GL_NV_blend_equation_advanced_coherent support.
RegalX11.cpp added for fake X11 purposes for GLX emulation.
GLEW refresh.
Fixups for REGAL_SYS_EMSCRIPTEN_STATIC mode.
GL_EXT_blend_color, GL_EXT_blend_subtract and GL_NV_blend_square emulation for ES 2.0.
ARB_shader_subroutine completeness for NV_gpu_program5 purposes.
Better log nesting for begin/end, push/pop log pairs.
Regal.cpp codegen tidy-up: reduce casting for default return values.
Regal context sharing for WGL too.
Log the return values of global functions (WGL, etc) in the driver logging stream.
Regal::Marker needs two versions of toString, depending on the relevant extension being emulated.
Application-side shaders in Regal.cpp via EmuCache.py
Driver-side shaders via RegalDispatchCache.cpp
Regal::Config support for shader chaching and readback.
REGAL_CACHE=1 global enable/disable of caching in general.
REGAL_CACHE_SHADER=1 enable/disable of shader caching (GLSL only, so far).
REGAL_CACHE_SHADER_READ=1 enable/disable readback from disk cache.
REGAL_CACHE_DIRECTORY directory for caching shaders.
Additional documentation for Regal logging.
For glUseProgram also log glGetAttachedShaders, if applicable.
Fixup for driver logging dispatch - log contents of output parameters too.
Consolidate driver logging dispatch to one line per call, including return value.
