* contrib/hbqt/qtgui/qth/QTreeWidgetItem.qth
! Fixed: regression as per prev commit.
QTreeWidgetItem() can receive another QTreeWidgetItem
as its child and hence is subject to not destroy Qt
object by Harbour.
* contrib/hbqt/tests/browqt.prg
+ Enabled: Build_TreeView() which was causing GPF on exit,
a result of above fix.