ENH: Added new events for proxy registration and unregistration (ParaView)

Common/vtkCommand.cxx

@@ -84,6 +84,8 @@ static const char *vtkCommandEventStrings[] = {
   "DomainModifiedEvent",
   "PropertyModifiedEvent",
   "UpdateEvent",
+  "RegisterEvent",
+  "UnRegisterEvent",
   NULL
 };
 

Common/vtkCommand.h

@@ -164,6 +164,8 @@ public:
     DomainModifiedEvent,
     PropertyModifiedEvent,
     UpdateEvent,
+    RegisterEvent,
+    UnRegisterEvent,
     UserEvent = 1000
   };
 //ETX