Merge branch 'master' of https://github.com/worklist/hifi into recursive_voxel_delete
Merge branch 'master' of https://github.com/worklist/hifi into gyroquat
Use quaternions for rotation estimates.
Enhanced workiness.
Merge pull request #496 from ey6es/master

Apply the head rotation to the head bones, show balls when no avatar voxel URL is set.
Acceleration is presumably relative to the current orientation.
Add back yaw decay the quaternion way.
Coordinate fix.
More compiley.
Approach the "down" direction more rapidly.
Merge branch 'master' of https://github.com/worklist/hifi into gyroquat
repair indentation and NULL comparisons in Avatar class
Merge pull request #499 from ey6es/gyroquat

Converted gyro rotation computations to use quaternions, fixed coordinates and increased rate of convergence to current gravity.
Check if our canvas has focus.  If not, then ignore events passed to it.
Use _mouseX and _mouseY for mouse look instead of the global mouse position when idle (prevents mouse look from accidentally triggering when the window is inactive).
Check if our main window is our application window within Application's event handling functions.
Removed double negation for coordinates, world aligned orientation -> camera
orientation, removed roll.
Added debug->run timing tests option to speed test some common functions  (please add some more, bottom of util.cpp
Add pitch/yaw scale preference to control degree of view rotation.
Think this needs to be a double.