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.
Merge branch 'develop' into fix_unnecessary_mysql_password_prompts

* develop: (70 commits)
  enable X-Forwarded-Hosts on staging for new projects
  add cleanup_sessions tasks
  Use host_list rather than fixed set of env values
  Allow uploads_dir to be set in project_settings.py
  Don't optimise dumps for rsync in get_remote_dump
  Use the default EMAIL_BACKEND not celery
  Add missing robots.txt for staging environment
  Create django uploads directory on deployment
  Disable DEBUG on staging servers.
  Fix an issue with django-filer, and upgrade a couple of other CMS apps.
  Fix --ignore-ve to allow running manage.py with no ve_mgr.
  Reduce default number of search results per page.
  Ensure that py.test exits with correct signal. Fixes #71
  Support reading version_info for Python <2.7
  Add jenkins local_settings template
  Updates to make DYE work with Django-CMS 3.
  Add extra note to release notes
  Set python version is project_settings and check in ve_mgr
  Make code to avoid bad syncdb call more readable
  Added syncdb for Django < 1.5 prior to migrate
  ...
Add a test_grants() method

So we can test if privileges have been granted without invoking the
mysql root user