[Feature] Sort by "last commented"

[logon84]

Hi. I like to have my collection updated with new hd videos and so. The calendar on the web site only shows new songs but not updated songs, so in order to see the last updated songs I can only look at the "new (last 10) comments". It would be nice to sort the songs in usdb_syncer by last comment (activity) done on the song section....or maybe easier to sort by song update date.