Catch more cases where ticket reinitialization is broken

If the identity service is started later than goa-daemon then it won't currently notify goa-daemon about tickets that expired before it was running.

Also, goa-daemon is sometimes slow to update the IsSignedIn property on the identity bus objects after notifying goa-daemon about expiration. This means goa-daemon doesn't bother to request reinitialization for those identities.

This merge request addresses both problems and also does some internal clean up to change which thread certain signals are emitted from to more closely match caller expectations.

This merge request also fixes bugs that lead to extra "expired" and "unexpired" signals getting emitted.