Move code from projects controller into projects service

Turns out one of angularJS's best practices is to put more code in services and barely any in controllers. Apparently the best approach is to have directives with isolate scopes, and let those rely on services for shared ...erm... services.

This is one step into that direction, but there will be more.

Most of this PR is just shuffling lines of code.

It will all make sense one day. I promise to write a small doc describing the guidelines behind the structure of angular code.