Fix for camera movement with webcam enabled; don't bother using roll from
webcam if we have the gyros; reinstate head orientation scaling; don't bother
using gyro position.
Not crazy about the rotation amplification.
Restore the amplification; blink faster.
Merge pull request #615 from ey6es/master

Fixes for gyros/webcam: restore rotation amplification, don't bother with gyro position or fusing webcam roll, blink faster.