APish posting clients

These posting clients more or less implement ActivityPub's client-to-server portion. Auth is with the Authorization header, nothing fancy, probably not very secure.

They post an ActivityStreams 2.0 object with the application/ld+json content-type.

Consider them experimental at best.

• burrow (code): for vague checkins.
• replicator (code): for food posts.
• no ceremonies are necessary (code): for notes and articles.
• latinum (code): for acquire posts.
• delta flyer (code): for travel posts.
• lore (code): for word count posts.

See also: extension vocab terms used by these clients.