Add headpat opt-out role

[hyperneutrino]

A way to opt out of getting headpats has been requested, so the configuration now allows roles to be set such that if a user has any of those roles, the bot will not automatically headpat them when they say something like "ababababa" or whatever (this also controls the 1000 message headpat, so that can be re-enabled as well if desired).

[MysticMia]

The problem is that this would require a staff interaction for a user to get/remove headpats. I feel it would be better if users can do this on their own end without needing one such staff interaction. I also want to rework the server ids setup. Since I already have a mongo database for guild information, these ids could fit into that; but the interface is not quite user friendly enough for it, and there need to be more module enable/disable options. Not all servers may want to have a starboard, for example. See also #17 and #24

[MysticMia]

(i misclicked the button and didn't mean to close it quite yet, but i think the rework would be better than adding a role on ahort term now anyway..) (further discussion in staff server too)