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.