[FIX] trackers: Fix drop-down menu of options for ItemLink fields when one or more of the multiple display fields are also ItemLinks

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52187 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] trackers: Nested ItemLink concat_item_from_fieldslist call was missing several parameters

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52188 b456876b-0849-0410-b77d-98878d47e9d5