Add btCollisionObject::setIgnoreCollisionCheck to disable collisions between specific instances, without having a btTypedConstraint. See https://github.com/bulletphysics/bullet3/issues/165
Make btMultiBody and btMultiBodyJointMotor backwards compatible with Bullet 2.82 API (single-DOF API)
Allow picking of btMultiBody, using a btMultiBodyPoint2Point constraint, with limited strength to avoid adding too much energy to the system (= blowup)
Add btMultiBodyJointMotor, it can be used in combination with joint limit (just add the joint limit after the motor, to avoid jitter)