3.0.13 release notes

Numerous documentation including installation and tutorial updates
Numerous improvements to translations
Improves reliability of Advanced Settings on page when using apphooks
Allow page deletion after template removal
Improves upstream caching accuracy
Improves CMSAttachMenu registration
Improves redirection as a result of changes to page slugs, etc.
Improves performance of “watched models”
Improves frontend performance relating to re-sizing the sideframe
Corrects an issue where items might not be visible in structure mode menus
Prevent accidental upgrades to Django 1.8, which is not yet supported