The following MNodeMessage methods differ from their C++
counterparts.
addNodeDirtyCallback(
node, func, clientData=None, status=None)
This is the version that registers the callback that takes the node, the plug
and the client data as input. The other functions that register the callbacks
that take fewer arguments are not available (just ignore the arguments you
don't need).
addNameChangedCallback(
node, func, clientData=None, status=None)
This is the version that registers the callback that takes the node, the
previous name and the client data as input. The other function that registers
the callback that takes fewer arguments is not available.
