Share statistics with webserver and/or rematch

[nirizr]

It would be extremely helpful for us to get statistics about matchers success ratios. This might be too soon to come up with this issue, and it might get some community disapproval, but knowing which matchers perform well will greatly help us put the correct efforts on additional matchers as well as optimize the matching process.

This should obviously be a default-off functionality, and perhaps only display a report in the webservice. Would be nice to benchmark performance for #181 as well.

• Have MatchResultsDialog Apply submit selected matches as accepted matches and store those in DB.
• Provide a user interface to undo selected matches.
• Display statistics based on accepted matches for a single task or for the entire database.