fix lib name issue with wxWidgets on mac
split premake4 (4.4b5) from premake5 (built from premake-dev sources)
default to premake5, add helper function to test for major premake version
add --no-graphics premake option to compile out graphics subsystem
fix assert on mac
Merge commit 'c727b214' into glfw_window

Conflicts:
	Helium.lua
	premake4.lua
First pass implementation of GL vertex buffer code.