BGE: Add property/material detection and X-Ray for mouse over any sensor

This patch adds a Property/Material detection and a X-Ray mode to the mouse over any sensor like on the ray sensor.

Proposal:
http://blenderartists.org/forum/showthread.php?261847-BGE-proposal-Mouse-Over-Any-sensor-with-Property-and-X-Ray&highlight=proposal

Reviewers: moguri

Reviewed By: moguri

Differential Revision: https://developer.blender.org/D653

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

@@ -64,3 +64,20 @@ base class --- :class:`SCA_MouseSensor`
 
       :type: boolean
 
+   .. attribute:: useXRay
+
+      If enabled it allows the sensor to see through game objects that don't have the selected property or material.
+
+     :type: boolean
+
+   .. attribute:: propName
+
+      The property or material the sensor is looking for.
+
+     :type: string
+
+   .. attribute:: useMaterial
+
+      Determines if the sensor is looking for a property or material. KX_True = Find material; KX_False = Find property.
+
+     :type: boolean