I added a quick command to make it easier to maintain or automate maintenance of Piwik. The command forces an optimization of one or more archive tables. I've noticed while supporting some users that even when using InnoDB, it can be necessary to rebuild archive tables. I also noticed, running the queries manually can be tedious and undesired (from the user's perspective), so I created this (small) command.
@tsteur Can you give this a quick review (or your thoughts if you don't think it should be merged)?
Added some notes but up to you. Feel free to merge