Fixed timestamp updating error (closes #42)
Added 500 error page and image.
Added missing static tag to 500 error page.
Updated 500 page (closes #44).
Removed breadcrumbs from 404 error page.
Added button to article view for releasing under CC BY-SA 4.0 license.
Expanded admin options for articles (closes #45).
Added admin action for releasing articles under CC license.
Limited articles that could be released under a CC license in the admin to only the author's own articles.
Added 'Recent Articles' fragment to the home page and adjusted the jumbotron on at the top.
Adjusted sort order of categories.
Fixed bug causing all articles to be displayed for categories.
Moved email template.
Added email for article submissions (closes #43) and added email settings to default local_settings.py.
Added some extra links to the footer (closes #39).
Added 2buntu branding to admin interface.