Allow pages to be dragged out of a subtree to the root level in page admin.
Check that setting a new page parent won't cause a cycle in the parent-child graph.
Such cycles lead to an infinite loop in ``Page.save`` (e.g. python process consuming all resources).
Protect sequences provided or generated for the default value of ``MenusField`` from being forced to unicode (as for example u'[1, 2, 3]').
Django forces fields defaults to unicode unless they're callable (see ``Field.get_default``). This is done to prevent problems that could arise from setting the same mutable object as a default for many fields (see Django ticket #18478).
Database-prepare tuples in the same way lists are handled in ``MultiChoiceField``.
Pep8, blank lines before inner classes.
Make the sites permission form in user admin translatable.
Added possibility to set custom menu titles for models in ``ADMIN_MENU_ORDER``, using the same notation as for views (e.g. (_("News"), "blog.BlogPost")).
Python 2.5 compatibility.
Use content_model not the base Page in PageAdmin

When calling methods on a page, they should be called on the subclass,
not the base Page. This allows page types to override them.
Merge
Merge
Merge
Update admin menu docs to mention labels for regaulr models.
Merge
pep8 fix