Django-text

UI enhancements and tests

- Fixed broken hide button in toolbar window
- PyPI release now available as wheel

This is a big rewrite for support of Django 1.8 and 1.9. (squash of 47)

With this release support for Django 1.7 and Python 3.2 and 3.3 is dropped, as they are no longer supported by Django.

Also introduces the `instant_update` templatetag keyword argument to fix 37.