can't reconnect to distributed session

```
What steps will reproduce the problem?
1. build a scenario, assign part to another server
2. start it, then exit without shutting down
3. launch GUI and attempt to reconnect; this causes errors

What is the expected output? What do you see instead?

The original topology should re-appear in the GUI.

Please use labels and text to provide additional information.

Objects not emulated on the master server are not instantiated there. The
Broker.handlemsg() will return False when messages should not be handled
locally, but forwarded. Forwarded messages do not create Python objects with
start=False.

```

Original issue reported on code.google.com by `ahrenh...@gmail.com` on 8 Dec 2011 at 11:18