Joint limits have no effect in multibody ball joints

[jsatka]

Enforcing the set joint limits for ball joints in 3D is missing in the multibody constraint solver. Regardless of the set rotational limits the ball joints revolve freely, as if there were no limits set.

Possible workarounds with caveats:

• Using impulse ball joint -> not ideal for robotics simulation due to joint drift
• Using a chain of three multibody hinge joints -> additional multibody complexity