Import only specific values from project_settings into env.

Prevents project_settings from accidentally stomping all over env, for
example overwriting env.path with garbage.

Fix invalid use of getattr.
create_copy_for_rollback removed upstream, shouldn't be here
crispy_forms is required by settings.py, so we must install it first.
Don't prompt for MySQL root password if not really necessary.

If we can connect, access the main database and create the test database then
everything's fine, we don't really need to ask for the MySQL root password.
Remove another djangoism