Add "default_layout" support, so the website layout knows howto behave when displaying a form (needed buttons & hidden fields,...).
Fixed some functions returning overcomplicated paths or returning just a title.
Improved breadcrumb generation : now can also use the short title if present.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@6296 20353a03-c40f-0410-a6d1-a30d3c3de9de