* In a previous update in 2021 many copyright ranges were truncated
accidentally, and some files have been copy-pasted with wrong years. These
dates have been fixed based on git history and original copyright messages.
* 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 used primarily for the buffer/mesh viewer to be able to pin
the index/element column to the left side, group columns together with
a noticeable separator, and other minor tweaks.
* Unfortunately due to tight private coupling and lack of virtual
functions in the QTableView and QHeaderView, a few unrelated functions
have to be re-implemented to point to our own header.
baldurk