API update

I feel like this has been a pretty productive update. I'm pretty confident in the state of the API at this point, although it will still change and evolve. There hasn't been a whole lot of changes you can see as a user, but there has been a lot of work behind the scenes.

• There is a brand new caching API to simplify the caching of resources
• Added !goldfish, !eat, !define, !randdefine, !lenny, !shrug, !tableflip, and !fart thanks to @Goldfish64!
• Sanitization of @here and @everyone
• Moved from using the now non-existing StarAPI to Starbooru
• Started work on a plugin reloading system to add, remove, and reload plugins on the fly