Add specialized django server and helper view

This request was caused by https://github.com/plq/spyne/commit/f4350ea65253a552dbcd8dbc2b41ddf93aafc38d

I've implemented separate DjangoServer that is talking with helper  view in Django HttpRequest/HttpResponse objects. It should be much cleaner way to integrate Spyne into Django comparing to wrapper around WSGI-application with wsgi.input monkeypatching.