Switch to GLEW from GLEE (which isn't being updated) and start factoring out GL 2.x stuff
Merge branch 'master' into GL3

Conflicts:
	kglt/renderers/generic_renderer.cpp
	kglt/ui/interface.cpp
	kglt/utils/geometry_buffer.cpp
	kglt/utils/gl_error.cpp
Continue work on the GL3 port
Finally make the UI stuff GL3 compatible, now for the rest of it!
Add new OpenGL call checking code, continue the GL3 upgrade
Clean up the VBO handling and use VAOs for mesh rendering. Always do a GLThreadCheck inside GLCheck
Fix loads of issues with rendering, but still the console refuses to display :(
Install hpp files as well as .h
Finally fix the console rendering bug!