Fix and improve editor state persistance for the VisualShader editor

Author: Geometror

doc/classes/VisualShader.xml

@@ -186,11 +186,6 @@
 			</description>
 		</method>
 	</methods>
-	<members>
-		<member name="graph_offset" type="Vector2" setter="set_graph_offset" getter="get_graph_offset" default="Vector2(0, 0)">
-			The offset vector of the whole graph.
-		</member>
-	</members>
 	<constants>
 		<constant name="TYPE_VERTEX" value="0" enum="Type">
 			A vertex shader, operating on vertices.