BUG - do_collection_search now returns array() if no results (for correct results count)

git-svn-id: http://svn.montala.net/svn/resourcespace@4646 c08608d7-6e46-0410-86ca-f2a6f1370df5
BUG - combine 4646 and 4645 for more unified solution (do_collection_search returns array as do_search)

git-svn-id: http://svn.montala.net/svn/resourcespace@4647 c08608d7-6e46-0410-86ca-f2a6f1370df5