Added versioning to permissions cache
Fixed a few typos in the cache versioning
Added versioning to clear_user_permission_cache, now passes tests
Start adding docs for how to test your extensions
Add docs for testing CMS plugins
use django override_settings decorator in cms app test examples
Add mention of CMSTestCase
Use links to django docs

as suggested by @piquadrat
Add link to reverse() function

from testing docs
Merge pull request #1807 from foobacca/testing_docs

Testing docs
Move PermissionModeratorTests._create_user method to CMSTestCase
Remove pages.css from PlaceholderAdmin

It is included in PageAdmin so it is unnecessary to include in
PlaceholderAdmin - and causes issues if users have admin classes
inheriting from PlaceholderAdmin

Fixes issue #1659
Add tests for permissions cache
Removed unused imports
Add test to check LogEntry added when pages edited via AJAX

This happens when using the page list - if you (un)check the checkboxes
for "published" or "in navigation" an AJAX request happens to do this
immediately.  However, until now, this has not added a LogEntry in the
way that the admin system does when you save an object in the admin
system.
Add LogEntry when changing page status via AJAX

Fixes issue #1603
Use --noinput convention for delete_orphaned_plugins command

delete_orphaned_plugins is a destructive command.  So by default report
how many things would be deleted and then ask for confirmation before
deleting them.  But if --noinput argument is used then don't ask for
confirmation and just go ahead.

Fixes issue #1591
Merge pull request #1819 from foobacca/delete_orphaned_noinput

Use --noinput convention for delete_orphaned_plugins command
Merge pull request #1817 from foobacca/log_admin_ajax_action

Log change of page status done via AJAX
Merge pull request #1818 from foobacca/placeholder_admin_css

Remove pages.css from PlaceholderAdmin