Fixed page_attribute template tag not escaping output
Added test for page_attribute escaping
2.3.5 release
removed two redundant icons; use Django's instead
Revert "removed two redundant icons; use Django's instead"

This reverts commit e353318fe7ccbb219391274ba8cdb774a3fbb275.
When creating a new language title for an existing page, do not update the slug on the other languages
Handle Title.DoesNotExist when fallback=False is used
test case for adding new language versions of existing pages
python 2.5 support for with statement
use assertRaises instead
use api.create_page instead of client.post
Merge pull request #1604 from benjaoming/support/2.3.x

Fix slug bug when creating a new language
Fix for issue #1555 and #1620: Page path rewriting when published page becomes the HOME page

* when CMS_MODERATOR = True:
  if the draft page is unpublished, the public version is also unpublished
* when determining the home page, ignore publication_date and publication_end_date
  this ensures that the home page path rewriting logic happens even if the page will only become available
     somewhere in the future
* change the post_save_page signal handler so that it also updates the:
  ** paths(titles) of the currently saved page
  ** if the currently saved page becomes the new home page, then update the paths(titles) of the previous home page
  ** if the currently saved page used to be the home page, then update the paths(titles) of the new home page
* add pre/post delete signal handlers that: if the currently deleted page was the home page
  then update the path of the new home page
* Added unit tests for all the above functionality

This ensures that:
* we will always have AT MOST one page with the '' (empty) path
* no matter what publishing method is used (tick the publish/unpublish checkbox in the page hierarchy,
    tick the 'is published' checkbox from the 'change page' view OR click 'publish' while doing frontend editing)
    the generated paths are consistent
Removed unused import
Better naming to the delete page signal handlers.
Renamed pre/post delete signal handlers and reduced the number of queries.
When determining previous home page's titles, filter by the current instance's site (otherise titles of home pages from all other sites are returned)
Removed logging imports
fixed cms not being installable if django is installed

fixes #1652
fixes #1651
Merge remote-tracking branch 'origin/pr/1647' into support/2.3.x
Release 2.3.6