Sitting and standing modes work even in desktop mode.
We were inadvertently checking for HMD Mode instead of if the head was valid.
* A change was made to the ViveControllerManager to return head poses in the correct standing universe when in desktop mode.
* The default sensorToWorld matrix in desktop mode is similar to the one returned by the system for Vive and Oculus sensor frame; y = 0 is at floor level.
* Sitting mode, walking mode and recentering flags are now visible in the AnimStats.
* During a state machine interp the previous state now shows up in AlphaValues panel, with parentheses around the name.
* Added 3 new fields
* Position - in world coordinate frame.
* Heading - the facing angle in the world corrdinate frame.
* Local Vel - the velocity of the character in the local coordinate frame. (left, forward, up).
