[fix bug 930571] Switch to django-compressor.

* Switch from jingo-minify to django-compressor
* Add django-jingo-offline-compressor
* Update jenkins
* Update local.py dists
* Update Chief command
* Delete unused qunit files and related libs.
Merge pull request #692 from glogiotatidis/compressor

[fix bug 930571] Switch to django-compressor.