Fix nginx config to work on more recent ubuntu versions.

Not sure how backwards compatible this is.
Please see: http://stackoverflow.com/questions/8768946/dealing-with-nginx-400-the-plain-http-request-was-sent-to-https-port-error
dynamically generate top margin of admin content area
contentMargin out of global namespace
Force csrf token generation on every request with cache middleware. Closes #676.
Use a more explicit name in PageAdmin.get_content_models which won't collide with a commonly used field name such as name.
Merge
Added Andromeda Yelton to AUTHORS.
Merge
Merge