Introduced new osg::discardDeletedOpenGLObjects() methods, and usage of it in

GrpahicsContext::close() to handle cases where deletingOpenGLObjects is no possible,
such as when GraphicsWindowEmbedded is used.

src/osgWrappers/osg/Program.cpp

@@ -195,6 +195,10 @@ BEGIN_OBJECT_REFLECTOR(osg::Program)
 	                __void__flushDeletedGlPrograms__unsigned_int__double__double_R1_S,
 	                "flush all the cached glPrograms which need to be deleted in the OpenGL context related to contextID. ",
 	                "");
+	I_StaticMethod1(void, discardDeletedGlPrograms, IN, unsigned int, contextID,
+	                __void__discardDeletedGlPrograms__unsigned_int_S,
+	                "discard all the cached glPrograms which need to be deleted in the OpenGL context related to contextID. ",
+	                "Note, unlike flush no OpenGL calls are made, instead the handles are all removed. this call is useful for when an OpenGL context has been destroyed. ");
 	I_SimpleProperty(const osg::Program::AttribBindingList &, AttribBindingList, 
 	                 __C5_AttribBindingList_R1__getAttribBindingList, 
 	                 0);