Use `usercouch` for live tests, always run them

[Jason Gerard DeRose]

So after a lot of fumbling around, I think I finally have way of starting a throw-away CouchDB instance for use in unit tests that I like, something like what's currently in dmedia.tests.couch:

http://bazaar.launchpad.net/~dmedia/dmedia/trunk/view/head:/dmedia/tests/couch.py

In the next few days I'm moving it to a new stand-alone component `usercouch`:

https://launchpad.net/usercouch

(To complement `userwebkit`, cute, huh?)

This way microfiber, novacut, and dmedia can all use the same CouchDB testing idiom... and importantly, one with minimal dependencies, especially no dependency on DBus.

So we'll change the base class for the live tests and have it call skipTest() if `usercouch` isn't available, but run the test by default when `usercouch` is available. And we should change the setup.py test --live option to --no-live, in case someone wants to run everything but the live tests (which is handy as the live tests take a bit to run).

[Jason Gerard DeRose (jderose)]

So I got the CouchDB unit tester from dmedia cleaned up, packaged, and brought it up to 100% test coverage. I'm currently waiting on a build:

https://code.launchpad.net/~novacut/+recipe/usercouch-daily

I'm doing the above build in part to test if we can run live CouchDB unit tests okay in the build environments. Assuming that works okay, we'll start running live CouchDB unit tests during all our builds (dmedia and novacut in particular are next up).