Add /maintainers/ API

Refactor code and moved a bulk of code from listeners.pulls to adapters.git where it belongs. This allows more ways to use the same underlying unit without having to have all of the logic.
WIP - Do not pull

This will not run/compile, yet. But is an implementation of the intended direction
Add maintainers/lead_maintainer API

Currently used by the Gordon bot to do auto assignment via github webhooks and report status to IRC.
Merge pull request #20 from dotcloud/add-maintainer-api

Add maintainer api