implement login form
LOGIN_REQUIRED ALL THE THINGS
add logout link (not a very nice one, but it'll do)
Lock down verdantusers app to users with can_change_user permission only
Record the user in page_revisions
Merge branch 'develop' into users
Merge branch 'develop' into users

Conflicts:
	django-verdant/verdantadmin/views/pages.py
add migration to add editor/moderator groups
add groups to the edit/add user forms
implement 'submitted' flag on page revisions
show listing of submitted pages
Show submitter on 'pages awaiting moderation' listing
implement moderation approval
implement moderation rejection
Started verdantmedia
moved logout link
removed non-functional ui
tweaks to action buttons
removing mention of unpublishing from pages that are already unpublished
add edit link to moderation panel