Merge pull request kobotoolbox#1170 from kobotoolbox/1169-issue

Revert django-reversion; standardize package names

Merge pull request kobotoolbox#1137 from kobotoolbox/1136-issue

Import `LOGIN_URL` at beginning of `settings.py`

Merge pull request kobotoolbox#1090 from kobotoolbox/access-owned-sna…

…pshots

Allow users to access their own source snapshots