Implement an additional safety.

Now, during a halt, RT Ops monitors the halt's progress and triggers the EStop if a motor is not decelerating correctly.
atc_canonical_walking now holds the hips in place during shutdown.
Adding manual tau control to atc_canonical_walking's GUI.
Adding torque limits to atc_canonical_walking
Added startup/shutdown checklists to atc_canonical_walking
Last little change to test firmware from weeks back.
Merge branch 'master' of https://code.google.com/p/atrias