Adds self-hosted, single-realm administrative functions to otouto.
Check out the README for a detailed description.
Also added msg.from.name, which is msg.from.first_name + msg.from.last_name (if it
exists), because I'm too lazy to build it each time.
Fixed a crash-causing bug (ironically) in the handle_exception() function.
Everything reworked and rewritten.
Antisquig is now a plugin to work with moderation.lua.
The bot can now upload photos, stickers, and other files.
Return values in plugin functions to affect the bot's behavior.
All this and more!
