jQuery Django `CRSF` helper should be `CSRF`.

See the [docs](https://docs.djangoproject.com/en/dev/ref/contrib/csrf/).
It stands for Cross-Site Request Forgery.

**Breaks backwards compatibility!**
Merge pull request #8 from rouge8/crsf-to-csrf

jQuery Django `CRSF` helper should be `CSRF`.
Updated changelog