Merge pull request #279 from birarda/oculus

initial setup for oculus pitch, yaw and roll
use capital L for lib directory for LibOVR
Merge pull request #280 from birarda/master

find incorrect reference to OVR library
another typo fix for unix reference to Oculus library
Merge pull request #281 from birarda/master

typo in name for oculus unix library
remove the source files from the LibOVR dir
Merge pull request #282 from birarda/master

remove the oculus lib source files, not required
optimized performance of VoxelNode::isLeaf()
Merge branch 'master' of https://github.com/worklist/hifi into render_voxels_optimization
CR feedback
Merge pull request #283 from ZappoMan/render_voxels_optimization

Optimized VoxelNode::isLeaf()
link the OVR library seperately from the QT_LIBRARIES
Merge pull request #284 from birarda/master

attempted fix for UNIX link order of LibOVR library
link to LIBOVR_LIBRARY before calling add_executable
Merge pull request #285 from birarda/master

another attempt to fix link issues
Revert "link to LIBOVR_LIBRARY before calling add_executable"

This reverts commit b2776f25ac3f655d3ca4c58221a57e94a8d7e2d9.
Merge pull request #286 from birarda/master

revert the last change
assume that oculus will only be from APPLE machines
Merge pull request #287 from birarda/master

conditionals in OculusManager for APPLE
condtional calls to constructors in OculusManager on APPLE only