Added versioning to permissions cache
Fixed a few typos in the cache versioning
Added versioning to clear_user_permission_cache, now passes tests
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
Merge pull request #1792 from TAMUArch/support/2.4.x

Cache Versioning on Permissions Cache
Merge pull request #1824 from yakky/feature/move_create_user_24

Move PermissionModeratorTests._create_user method to CMSTestCase
Merge pull request #1825 from yakky/feature/permissions_cache_tests_24

Feature/permissions cache tests for #1792
Added option to render_placeholder tag to set language

This is helpful in cases where the content of a placeholder in a specific
language should be displayed, independent of the user's language.
some documentation about the language argument for the render_placeholder tag
Adding some information on using pip and virtualenv
Merge pull request #1879 from piquadrat/feature/render-placeholder-language-2.4

Added option to render_placeholder tag to set language (2.4 branch)