start to implement real UI

I finally figure out a way to make restangular like jsonapi's output better.

This open the way to a few more pages.

I got up until I can find some bugs and incoherencies in the data api.

- steps endpoint seems to return empty list, even after I fixed the obvious missing yield issue.
- missing endpoint for buildrequest
- having buildsetid in build endpoint will help much building the "build" page.
- steps urls had names at some point? now its only one string.
- dynamic build properties look unimplemented yet ?
- state string mismatch compared to getText[2]() in legacy webstatus. (can only see "created" status)

apart from that, the api is great to use, and the filtering is very cool.