* This allows us to add rich text support much more easily into other itemviews
like RDTableView.
* We set it up for debug messages so that resource links in debug messages can
be linked.
* This is supported currently in the API inspector, constant buffer previewer, and resource inspector.
* The saved expansions are only saved while the capture is open, and will be reset each time.
* This item delegate will forward on either to a specified other
delegate or to the base implementation. This allows chaining delegates
(i.e. having one built-in to the widget, which forwards to a user-set
delegate).
* There's a messy order-of-operations thing to deal with various
different themes, as well as a couple of minor problems, but at least
the highlight and selection bars draw fairly consistently and don't
leave an ugly gap over the branches.
* This still isn't perfect with some custom style stuff but it's next
to impossible to get working right. In theory we should manually
draw PE_PanelItemViewItem in the gap in drawRow() or so to make sure
we also draw any on-hover highlight over objects, but that doesn't
seem to work.
baldurk