Merge pull request #272 from ey6es/master

Improvements to voxel editing: show what you'll be adding/removing/coloring, allow adjusting the desired size.
Re-added Head Mouse working correctly with invensense
Merge remote-tracking branch 'upstream/master'
Merge pull request #273 from PhilipRosedale/master

Re-Added Head Mouse for Invensense
Added a stub for a Qt application class that creates a menu (which, since it's
unparented, will only appear on OS X) with a test item connected to a slot.
Merge branch 'master' of https://github.com/worklist/hifi