Write a small tool for admins of PQM to give useful history information.

PQM does a lot of work for users, and the output is visible as commits on the relevant branch, and while being processed in the webui. It would be helpful as an admin to be able to answer a few common requests without digging in log files:

 * Did you get my merge request for $branch
 * What merges succeeded/failed over the last $timeperiod

In particular this can be used to highlight failing branches that may have failed due to PQM issues - uncaught exceptions - rather than tested-code errors which PQM forwards to the user.