#10 Exceptions during file load or save not handled correctly.

[Mark Soderquist]

If an exception occurs during a file load or save it
does not seem to be handled correctly. Various
side-effects have been noticed:

1. Undo/redo not working correctly. This is probably
due to the hash code not being set correctly when saving.
2. Save All action left active after all resources have
been closed. This is probably due to the save event not
getting propagated.