CRUD experiment successful : django-pstch-helpers becomes django-crucrudile, merge in master !

The `crucrudile` (and obsolete `newcbvs`, `newtmplmxns`) branch was started as an experiment to see if `django-pstch-helpers` could become more simple and more reusable.

I'm happy with this cleanup, and can now merge the `crucrudile` branch into `master`.

For the record, I don't need any more the other functionalities provided by `django-pstch-helpers`, because I realized that `django-braces` (+ some other packages) provide all of what I needed for my projects.

Why the fuck am I saying all these things ? I'm just talking to myself..