Allow configuration using commands.

Moved client_secret and client_id to automatron.ini file. Added
youtube-auth and youtube-playlist commands. Removed
automatron-youtube-setup script.
Use getPage to refresh access token.
Cleanup _request method.

Removed some code since it's only used for json requests now.
Defer access token updating to a lambda function.

This prevents needlessly passing along client and channel everywhere.
_youtube_request query can't be None
Rewritten almost everything.

- Uses txgoogleapi (https://github.com/iksteen/txgoogleapi) to access
the Google APIs.
- Added playlist rotation.
- Allows configuration using query commands.