(drag an item from an embedded collection to another embedded collection don't work yet)
git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@4352 bfdf4180-ca20-0410-9c96-a3a8aa849046
We must to use elementcollectionhandler instead
git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@4343 bfdf4180-ca20-0410-9c96-a3a8aa849046