Allow a single BCC address in addition to list/tuple

BCC fails if the addr_bcc argument is a single address rather than a list/tuple. This commit wraps a single address in a list to fix this problem.
Make sure request._messages has been set before trying to access it

This is for cases where the MessageMiddleware hasn't had a chance to
run, e.g when a previous middleware returned an exception.
Merge.
Use a separate key setting for nevercache tokens.
Remove print
Remove field related to Django built-in user model

South is expecting those fields to be in the database. So it is
selecting them, since some custom user models don't have them, this can
break this migration.
Version bump to 1.4.9
Added tag 1.4.9 for changeset 8f36e641249e
Update auto-generated CHANGELOG, settings docs, requirements.
Added window.__language_code variable to admin and inline loader
Better error message for page models that get removed from INSTALLED_APPS. Closes #722.
Merge.
Allow initial user creation in syncdb when a profile model is managed by migrations and doesn't yet exist.
Added Antoine Catton to AUTHORS.
Looser AJAX response check for page reordering. Closes #727.
Allow key settings to be defined in fab conf and injected into live local_settings module.
Merge.
Added mezzanine-wymeditor to third party apps in README.
Added valid Polish messages for mezzanine/core. Closes #729
Added Marek Wywiał to AUTHORS.