It would be useful for built-in commands to generate API events.
For instance, an API script could perform a sanity check whenever
the user opened a design.
This can be hacked at the moment by using another thread to periodically
invoke the script which can walk the Fusion object tree looking for changes.
However, if such a kludge runs too often it could slow Fusion down,
if too infrequently, the user won't get an immediate responsn to an action which
will be annoying.
