Changes

Fix build if oculusvr-sdk submodule is missing

GLU: Make ProjectFloat/ProjectDouble final and deprecate GLU.destroy() method.

Enhance FloatUtil: Merge ProjectFloat features while adding optimized variations; PMVMatrix: Remove NIO buffer path, use backing-array only and FloatUtil direct.

- FloatUtil pptimized variants:
  - mapObjToWinCoords (gluProject) passing 'P x Mv' for batch operations

  - mapWinToObjCoords (gluUnProject) passing 'Inv(P x Mv)' for batch operations

  - mapWinToObjCoords (gluUnProject) passing 'Inv(P x Mv)' and two winz values
    for two ray picking resulting in two obj positions. (-> mapWinToRay)

- PMVMatrix
  - dropped low performance NIO mode
  - simply use common backing-array and fixed offsets directly
  - drop ProjectFloat usage in favor of FloatUtil
  - reduce number of temporary arrays