fix bug 1045796 - remove/redirect links to derby
Don't let the session cookie expire.
[bug 1045796] keep derby page, change derby content
fix bug 1045796 - pull down devderby

fix dupe listing on landing page

update previous challenges config value to include all previous challenges
Added an own Persona provider that adds a session modification hack that existed in the pre-allauth code to work around a session cookie optimization in Zeus for the frontpage.
Fetch the CSRF middleware token from the site before submitting the Persona form.
Merge pull request #2667 from mozilla/session-debugging

Fix session problems with Persona backend. Fix bug #1046568.
Updated allauth to latest official release (0.18.0).
update tests
Merge pull request #2668 from mozilla/allauth-0.18.0

Updated allauth to latest official release (0.18.0).
Merge pull request #2665 from groovecoder/devderby-pulldown-1045796

fix bug 1045796 - remove devderby links