Added Object::resizeGLObjectBuffers(uint) method to help improve the ability

to change the number of active graphics contexts on the fly during an applications
life.

include/osg/StateAttribute

@@ -312,10 +312,13 @@ class OSG_EXPORT StateAttribute : public Object
           */
         virtual void apply(State&) const {}
 
-        /** default to nothing to compile - all state is applied immediately. */
+        /** Default to nothing to compile - all state is applied immediately. */
         virtual void compileGLObjects(State&) const {}
 
-        /** release OpenGL objects in specified graphics context if State
+        /** Resize any per context GLObject buffers to specified size. */
+        virtual void resizeGLObjectBuffers(unsigned int /*maxSize*/) {}
+
+        /** Release OpenGL objects in specified graphics context if State
             object is passed, otherwise release OpenGL objexts for all graphics context if
             State object pointer NULL.*/
         virtual void releaseGLObjects(State* =0) const {}