Distributed Roadmap

I want to add the ability to split a bot up into several co-ordinating parts.

Essential processes:

• [x] Add ContextVar support to curio (see: dabeaz/curio#254)

  • Trio already has this (thanks to yours truly), so that's not an issue.

• [x] Make dataclasses use a ContextVar for the bot object.

  • This makes them pickable, which means they can uploaded somewhere or sent over a network.

Curious core changes:

• [ ] Change the eventbus API significantly.
  • To be decided on.

Then, a distributed wrapper will be made.