Improvements to the command system.

[e3ndr]

As suggested by some people:

• The ability to limit a command to certain roles (MODERATOR, SUBSCRIBER, etc).
• General UI improvments.
  • The list is cumbersome, we need to find a better way of displaying that.
• Move the chatbot stuff from flatfile to the database.
• Unify Shouts and Commands.
• Better typings for events.
• A reward points currency system for cool commands.
• Better default commands, maybe a marketplace so you can share your own?