a basic home timeline

DistributionWorker. That isn't the heaviest service, yet, but gotta start
somewhere

(But there are no Atom feed pagination elements yet)

relations on Status#mentions

simplify FanOutOnWriteService, add /api/accounts/lookup method

fix tests (the recorded Salmon fixture expects LOCAL_DOMAIN to be something
specific unfortunately)

POST /api/statuses                  Params: status (text contents), in_reply_to_id (optional)
GET  /api/statuses/:id
POST /api/statuses/:id/reblog

GET  /api/accounts/:id
GET  /api/accounts/:id/following
GET  /api/accounts/:id/followers
POST /api/accounts/:id/follow
POST /api/accounts/:id/unfollow

POST /api/follows                  Params: uri (e.g. user@domain)

OAuth authentication is currently disabled, but the API can be used with HTTP Auth.