page list admin: fix select/deselect all pages
page list admin: fix select/deselect all pages

checkboxes for changed items in the list after expand/collapse/move pages
did not interact properly with the select/deselect-all checkbox

akaihola/django-page-cms,remik/django-page-cms,pombredanne/django-page-cms-1,batiste/django-page-cms,remik/django-page-cms,remik/django-page-cms,akaihola/django-page-cms,batiste/django-page-cms,pombredanne/django-page-cms-1,batiste/django-page-cms,remik/django-page-cms,akaihola/django-page-cms,pombredanne/django-page-cms-1