Ensure that service routers do not return exceptions.

Also return inline_message where appropriate.
Show a success message when the service key is set properly.
Add copyright notice to __init__.py.
Remove the PagerDuty account info on uninstall of the ZenPack.

If we don't do this, zendmd fails to start (since we hang our own data
model off of /zport/dmd).
Removed a commented out line.