Add a cog for ticketing / responding to reports or to deal with drama

[geirawsm]

Sort of a ticketing bot:

Setup:

• [ ] Creates category with custom name
• [ ] Creates a channel with only a button and a simple explanation for initiating separate channels

Manual use:

• [ ] Button available for mods
• [ ] Button creates a random channel within category
• [ ] Button can invite one or more extra users into the channel (and only that channel)

Automatic cleaning:

• [ ] Archiving or deleting old channels?