Trying to simulate Oculus Rift CV1 rendering without the device... for
Debug pourposes.

Still working on the sample but almost finished. Some rlgl internals
redesign required and it will be ready!

Now GLFW3 windows/context creation works ok and a sample red rectangle
has been drawn using rlgl. Next step is working in tracking
position/orientation maths and try to get a simple 3d scene...