Changed test for custom class in logout link

browserid-logout class should always be there.
Set mandatory class for logout button
Fixed logout button on Python 2.6
Simplified check for browserid-logout class
Added default class or login link as well
Fixed class ordering. Tests passing on Django 1.4

assertHTMLEqual was kind of dumb before Django 1.5
Add seocam to AUTHORS.rst.
Rework the auto-login docs

I reworked the auto-login docs turning the instructions into lists of
steps and breaking up the text into an "enable" section and a "disable"
section. I think this is easier to read. It's certainly easier to
follow.

Further, I think this addresses the confusion around what happens if
you're not using "django_browserid.helpers.browserid_js" regarding
"browserid/autologin.js" since it explicitly addresses it in the
relevant areas as a discrete step.

Fixes #267
Fixed issues from PR comments