Change nudge UI to be more consistent with classic editing UI.
Add menu option for Delete and fix delete for VoxelSelectMode.
Add ifdef for OS X to show delete hotkey in edit menu
Put upper bound on increasing nudge precision (i.e. making the nudge
less precise).
Merge pull request #936 from LionTurtle/master

Change nudge UI to be more consistent with classic editing UI.
Merge branch 'master' of https://github.com/worklist/hifi into add_fs_data_in_head_data