We'll trust that on startup the topic was in an OK state. If this is not so, making an action (or taking advantage of the new command "refresh") will fix it. This is to reduce topic spam when restarting harold for configuration changes.
This better fits the separation of concerns as deploy.py shouldn't know IRC syntax.
It's a bit over-zealous. Not all mentions are commands.
This means we don't have to use client certs for everyone that wants to view code review status and makes things a bit more general purpose.