Use "Document Type" rather than "Portal Type" when contributing a document.
Do not allow use to select  "Document Type" when contributing a link (it's to be determined by ingestion system).

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@35371 20353a03-c40f-0410-a6d1-a30d3c3de9de