URDF/SDF: add a flag to force concave mesh collisiofor static objects. <collision concave="yes" name="pod_collision">
VR: support teleporting using buttong, allow multiple controllers to be used, fast wireframe rendering,
Turn off warnings about deprecated C routine in btScalar.h/b3Scalar.h
Add a dummy return to stop a warning
Expose defaultContactERP in shared memory api/pybullet.
First start to expose IK in shared memory api/pybullet (not working yet)
Uses Kuka IIWA model description and 4 methods:
Selectively Damped Least Squares,Damped Least Squares,
Jacobi Transpose, Jacobi Pseudo Inverse
Tweak some PD values in Inverse Dynamics example and Robot example.
