AngularJS-ification of the Web front-end.

This seems to bring parity of functionality, with less boilerplate.

I also took the liberty to change the `/query` endpoint slightly, to avoid duplicating some logic in there.

/cc @sosedoff .. btw, thanks for starting this :)
The use of $rootScope is not justified here. You should use service instead to store global state. It's much more extendable that way.