Expose to about page by registering as a service

This is an attempt at handling the case where the workflow notifier stops calling avalon.  I'm hoping that by registering as a service and exposing it on the Avalon about page we can at least see that this has happened.  If this is due to something other than this module shutting down, then I think our best hope is bumping the logging level to trace or debug and watching the log file.