Made JointState transforms private.

Also changed some function names to be more descriptive.
Using "Hybrid" to describe frame with world-rotation + model-local-origin.
merge andrew/inertia into andrew/ragdoll

Conflicts:
	interface/src/avatar/Avatar.cpp
	interface/src/renderer/Model.h
remove 'fromBind' argument to getJointRotation()
unravel rotation code by giving proper names

The goal is: eliminate dependency on JointState::_combinedRotation
(which is joint-to-world) and store joint-to-model transforms instead
rolling back previous change for IK instability
Add joint manipulations in model-frame
Add more model-frame methods
remove world-frame hand/palm set methods
remove JointState::getJointRotation()

(use getRotationModelFrame() instead)
remove JointState::applyRotationDelta()

(use JointState::applyRotationDeltaInModelFrame()) instead)
FinalOrientation -> FinalOrientationInWorldFrame
remove some JointState::getHybridTransform() calls
getJointPosition -> getJointPositionInWorldFrame
remove more getHybridTransform() calls
remove JointState::getRota/PositionInWorldFrame()

instead: use getRotat/PositionInModelFrame() and do math
remove JointState::setRotation()

instead use JointState::setRotationInModelFrame()
remove JointState::_combinedRotation

instead use JointState::_rotationInModelFrame
remove last world-frame transfoms from JointState
renames of JointState data members
computeTransformInModelFrame -> computeTransform