Add ability to filter by username

[bap14]

Extract username from the message when recording and save it as a new column in the db. This will allow for filtering by username. The best move forward for mccxiv/tc#277

[mccxiv]

still TODO: ALTER TABLE on boot to add the username column

[bap14]

New pull request which solves this for you. Just need to verify it. Will not migrate older data (though a simple script could be run on the database to fix it).

[mccxiv]

Yeah that's good enough. Data is only kept for two days anyway so eventually all rows should have a username