Update Geometry and BufferGeomery docs for .userData

Author: takahirox

docs/api/core/BufferGeometry.html

@@ -185,6 +185,12 @@ <h3>[property:String name]</h3>
 		Optional name for this bufferGeometry instance. Default is an empty string.
 		</p>
 
+		<h3>[property:Object userData]</h3>
+		<p>
+		An object that can be used to store custom data about the BufferGeometry. It should not hold
+		references to functions as these will not be cloned.
+		</p>
+
 		<h3>[property:String uuid]</h3>
 		<p>
 		[link:http://en.wikipedia.org/wiki/Universally_unique_identifier UUID] of this object instance.

docs/api/core/Geometry.html

@@ -174,6 +174,12 @@ <h3>[property:Array skinIndices]</h3>
 		</code>
 		</p>
 
+		<h3>[property:Object userData]</h3>
+		<p>
+		An object that can be used to store custom data about the Geometry. It should not hold
+		references to functions as these will not be cloned.
+		</p>
+
 		<h3>[property:String uuid]</h3>
 		<p>
 		[link:http://en.wikipedia.org/wiki/Universally_unique_identifier UUID] of this object instance.