BGE: added clamping of angular velocity.

Angular velocity clamping was missing from the BGE. It is implemented
similarly to the linear velocity clamping. It is needed to be able to
drive physical simulations of systems that have a limited rotational
speed.

Reviewed by: campbellbarton, panzergame, ton

Differential Revision: https://developer.blender.org/D1365

doc/python_api/rst/bge_types/bge.types.KX_GameObject.rst

@@ -139,6 +139,29 @@ base class --- :class:`SCA_IObject`
 
          A value of 0.0 disables this option (rather then setting it stationary).
 
+   .. attribute:: angularVelocityMin
+
+      Enforces the object keeps rotating at a minimum velocity. A value of 0.0 disables this.
+
+      :type: non-negative float
+
+      .. note::
+
+         Applies to dynamic and rigid body objects only.
+         While objects are stationary the minimum velocity will not be applied.
+
+
+   .. attribute:: angularVelocityMax
+
+      Clamp the maximum angular velocity to prevent objects rotating beyond a set speed.
+      A value of 0.0 disables clamping; it does not stop rotation.
+
+      :type: non-negative float
+
+      .. note::
+
+         Applies to dynamic and rigid body objects only.
+
    .. attribute:: localInertia
 
       the object's inertia vector in local coordinates. Read only.