Add support for namespaced models to the resource generator

[jensljungblad]

This is what remains of #57.

Namespaced models are supported, but cannot be generated using the resource generator. The rails resource generator can create namespaced models, controllers and routes if passed a name on the form foo/bar. We should support this too.

Perhaps we can hook into rails generators?

There is a rails generator for creating routes: bin/rails g resource_route blargh/blorgh.