Django-assets

- Support Django 1.8 (various contributors).
- Drop support for Django 1.6.
- Windows fixes.

- Match webassets 0.11.

- Improve staticfiles/testing integration.
- Support Python 3.
- Face race condition during assets.py collection.

Based on 0.7-state from webassets core repository.

- Staticfiles integration now allows for globbing.
- Better document staticfiles support.
- Fix encoding errors raised by the template filter (Nikolai Prokoschenko).