Updates to the flush rendering objects function calls to allow for

managment of amount of time available to do gl delete's.  This control is
required for constant frame rate applications.

include/osg/VertexProgram

@@ -188,7 +188,7 @@ class SG_EXPORT VertexProgram : public StateAttribute
 
         /** flush all the cached vertex programs which need to be deleted
           * in the OpenGL context related to contextID.*/
-        static void flushDeletedVertexProgramObjects(unsigned int contextID);
+        static void flushDeletedVertexProgramObjects(unsigned int contextID,double currentTime, double& availableTime);
 
         virtual void apply(State& state) const;