Proactively notify admins when repo pauses/restarts X amount of times

The application index is designed to process indefinitely to overcome common network problems so that when connectivity is lost, the application will attempt to index the previously failed block of revisions again. While this works most of the time, a method to notify users/admins of (a configurable number of) failed index attempts would help admins be proactive about failures as opposed to hearing about it from end-users.