Fix SearchCtrl spec
Make resource a factory-like service

Check the comment in resource.service.js.
Add configurator.provideResource

Provides a new resource object retrievers (and savers) can later on use.
The configuration of this object is currently a little hacky.
Add conf setting for retrievers

They are used to configure our resource objects
Use resource in treebank and bspMorphRetriever
Add comment about an encoding issue in resource