wip: campfire hook changes

Behave more like a "good" plugin

- reduce complexity
- remove tinder dependency
- support more (all?) events
- update metadata

Potentially breaking changes

- less verbose (limited to one post per event)
- removed option to prevent
- requires room_id instead of room name

Unfinished
- needs tests

Still bad

- modifies the payload

Without being able to change the campfire api, I'm not sure how else to improve this hook

Conflicts:
	Gemfile.lock