minor cleanup
added MyAvatar.setMotorVelocity() & friends for JS
Fix for vertical jitter when walking on floor
scripted motor params are now Q_PROPERTIES
merge upstream/master into andrew/ragdoll
headMove.js using experimental avatar motor
fix vertical jitter (for real this time)
initial tuning of headMove.js for avatar motor
Merge pull request #3444 from AndrewMeadows/ragdoll

headMove.js uses avatar motor