[FIX] trackers: Replacing r43697 with a better (hopefully) fix for header field descriptions. Previous fix caused other field descriptions to no longer be directly under the field input. Also makes toggle for the header field work on tiki-view_tracker_item.php view and edit item tabs.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49580 b456876b-0849-0410-b77d-98878d47e9d5