Bug 1021: Fix OculusVR detection, need to probe HMD count, otherwise native SDK code crashes w/ NPE
Bug 1021: Refine Stereo API; Fix GenericStereoDevice; Fix StereoDemo01 for movie playback and OSX usage (HiDPI surfaceSize)

- StereoDevice.DeviceType: Add API doc

- StereoDevice: Add getFactory()

- GenericStereoDevice
  - Use common static vars for configurations for simplicity

  - Fix createRenderer(..)'s eyeViewport in case no post-processing
    is performed, i.e. needs viewport X offset.

- StereoDemo01
  - Use 'movie' eyePosition instead of default if:
    - using a movie player _and_ using lenses!

  - Fix NEWT window pixel-unit size after window creation!
NEWT Window setSurfaceSize(..): Add API doc comment about setting pixel-unit size after creation in multiple monitor mode.