We can now skim attachments out into many destinations.

* Replaced cuttlefish with multi-fs.
* Removed the dependency on mcouch; restructured signficantly.
* Added bunyan logging output for more diagnosible logs.
* Added 'log' events to emit debugging information.
* Switched from tap testing to lab testing.
* Expanded the tests somewhat & based them on a couchdb snapshot starting point.
* Tweaked command-line options slightly.
* Added semicolons like a stodgy person.
* Added a functional test in `npm run dev` that skims from fullfatdb into
  a local couchdb.