Revert "rest handler options"

I am afraid I misunderstood how the remoting options are implemented and gave a wrong advice on how to implement this whole feature :(

At the moment, all other remoting options are read from `remotes.options`, which are set from `app.get('remoting')` the first time `app.remotes()` is called (typically when a first model is attached to the app).

I don't want to introduce a new inconsistent way of configuring the remoting adapters, thus I have to revert strongloop/loopback#708