Update django to 1.6.4
Merge pull request #264 from jvc26/update-django

Update django to 1.6.4
Remove explicit --use-mirrors flag
Allow external (fix for latest pip packages)
Remove argparse as this is not required in Python 2.7+
Remove external links
Fix broken builds, allow all external packages
Merge pull request #268 from jvc26/fix-mirrors

Remove explicit --use-mirrors flag
Merge branch 'master' into update-dependencies