Read-only mode is a setting an admin can enable to prevent writes to

the database. This can be used when the site is under maintenence or

being upgraded. This commit adds some new documentation on how

extension authors can utilize read-only mode in js and django.

This commit also includes unit testing for the wrapped login_required

decorator and its usage to redirect New Review Request and My

Account when in read-only mode.

Build docs - no problem

Run python tests - pass except a couple that will be fixed in next commit