fix for empty field search, did not recognize empty fixed list entries (',') as empty

git-svn-id: http://svn.montala.net/svn/resourcespace@4401 c08608d7-6e46-0410-86ca-f2a6f1370df5
another fix for empty field search, for adding additional keywords to the search

git-svn-id: http://svn.montala.net/svn/resourcespace@4402 c08608d7-6e46-0410-86ca-f2a6f1370df5