enable experimental Mac OSX OpenVR, tested using Apple External Graphics Development Kit.
update to latest OpenVR 1.05 SDK from https://github.com/ValveSoftware/openvr add keyboard support to tune default camera VR position VR revert to double 'distorted' views on Desktop, since the single view isn't showing full scene
(Windows-only first, later Linux and OSX) Use premake to build, use --enable_openvr flag