Removed conditional for testing tracking state.
This fixes #23
Use vertex buffer objects instead of displaylists for the distortion mesh.
oculusviewconfig should only be included if USE_VIEW_CONFIG variable is set.
Added PixelsPerDisplayPixel as argument to constructor of OculusDevice.
Changes to support SDK 0.4.3

The function ovrHmd_GetEyePose() has been renamed to ovrHmd_GetHmdPosePerEye().

In the struct ovrEyeRenderDesc the field ViewAdjust has been renamed to HmdToEyeViewOffset.