Config reload

I redid the repo config page in angular, and took the opportunity to modify the way we manage per-plugin config.

The biggest thing I changed the way data is loaded; it's all consolidated now. Plugins, in the "project_config" panel, also give a "data" attribute, which specifies what data needs to be loaded for the UI to work. This can either be a string or list of strings (in which case they are just attributes on the main `repo_config`) or a function of the signature `fn(user, repo, models, next(err, data))`.

The data that's collected is then made available on the front-end to the angular controller for that plugin.

Because of this API change, we should probably bump a major version, and make sure all of the plugins specify a `peerDependency` of the proper version.

### Fixes
#142 Delete Github webhook fails
#42 Project config page has too many round trips on initial load

The only redesign I did so far was on the collaberators page:
![selection_028](https://f.cloud.github.com/assets/112170/867782/e79b4988-f733-11e2-90a6-5de3c2d17fb4.jpg)