use URDF_GLOBAL_VELOCITIES_MB flag in PyBullet loadURDF.
fix robot_bases.py due to new fields in getJointInfo.
backward compabitibility: BulletMJCFImporter, keep creating btMultiSphereShape for MJCF capsules with fromto, instead of shifted btCapsuleShapeZ, unless if CUF_USE_IMPLICIT_CYLINDER is used.
vr_kuka_control.py: control all joints, use analogue button to close gripper
remove some debug warnings/prints
pybullet, avoid crash in changeUserConstraint if not passing a [list]
allow some gym environments (pybullet_pendulum and locomotors) to re-use an existing physics client connection.