Features/improve translations

hello @effkay 
this are my proposals for improving translations in shoestrap.

what i did:
* in show.html the human attribute name is used for labels
* navigation item translations are put into shoestrap.yml with key cms.navigation.items
* shoestrap.yml is put into /de/views/cms folder
* for the new xxx button ond index the whole site path is used -> t('.new')

what do you mean?