coverage changes
Add app name to "no menus" warning message

Retry messed up pull request #1028 from 3 years ago. :)
Merge branch 'develop' of github.com:divio/django-cms into develop
fixes #3050
Merge pull request #3051 from digi604/fix-3050

Fix 3050 (page types on multiple sites)
Fix check on request.GET while request == None
slug collision checks for page types
Merge pull request #3053 from digi604/fix-3049

slug collision checks for page types
Merge pull request #3052 from derenio/fix_none_request_in_cmstoolbar_tag

Fix check on request.GET while request == None
Merge pull request #3042 from intgr/app_menu_warning

Add app name to "no menus" warning message