Review! New core

[Jeff Lindsay]

Because I'm hoping to have a working version of all this stuff by
PyCon, the easiest thing for me is to just create a new branch
(ginkgo) and start over, pulling from gservice where appropriate. A
lot of it is getting left behind for now (root service, named
services, catch, ...). I also brought in my work on the state machine
branch.

I figured I should get feedback as frequently as possible. So last
night I implemented BasicService, Container, Service, and an
AsyncManager that for now is hardcoded for gevent. I haven't actually
run this code yet, so shame on me. But I'm pretty sure I wrote most of
the initial gservice code that way too. Some sanity tests will be
added as I flesh it out more.

Until then, please code review my recent push to the ginkgo branch!
https://github.com/progrium/gservice/commit/c2f9cd22972d48d3feb1e35c7fd87a321876ce49