Add Measure_Num specializations for Rotation and Transform to allow Measures with those as values.
- sample full pelvis pose of the real robot and use it to correct the gravity direction in the model robot
- make pose control optional, controlled with 'p'
- weld the feet and add a sinusoidal prescribed motion to the pelvis
- limit torques, but to 10X the specified values (to avoid crashing)
- add new urdf full model with free pelvis, using Bushing joint for world->pelvis