Merge pull request #793 from inthause/documents

Add displayDocument property on StaticPage document.
Marking a page as index make visible twice
fixes #770
Add default values for model properties
Fixed default values in editors.
Add default values for model properties
Merge pull request #794 from fredericbonjour/Admin

Fixed default values in editors.
Fix tests
Fix action 'activate', 'deactivate', 'freeze' and 'unfreeze' on documents with correction