Groups: new tests and cleanup.
Rename 'group' db table to 'groups_group'.
Common: new tests and cleanup.
Users: Cleanup and url namespace.
Move UserFactory from 'common' to 'users' app.
Introduce PrivacyField model field.
Users: cleanup and new tests.

- Move views to phonebook app.
- Move RegistrationMiddleware to phonebook app.
Users: Tests and bug fixes for tasks.
Update jenkins test command.
Add memcache module.
Add initial product_details.
Phonebook: Update tests.
Phonebook: Url namespace.
Phonebook: Cleanup