Integration Request 6

Here's the last pull request. Sorry for the delay :)

### New

- Improved CSS
- Migration scripts for TagStats model
- Massive performance improvements
- Bugfixes
- Deployment docs
- Test VM configuration (Vagrantfile)

### Migration guide

1. Create new table

    sqlite3 /path/to/database
    sqlite> .read sql/issue294_create.sql

2. Migrate existing sessions

    ./manage.py shell
    >>> execfile('sql/issue294_migrate.py')