* Add scroll areas for the larger tabs and allow pipe flowchart to
resize to its minimum size if needed.
* The idea here isn't that anyone will seriously try to use the pipe
view at 500x200 but more that the minimum size doesn't become a
problem while moving around windows or panels, or resizing temporarily
* This was only added because the default tree widget controls don't
render any grid lines. Now that we're custom drawing them, the row
colors are distracting and can be confusing on themes where the
selected row is very faint.
* Since we're promoting everything, we reset the behaviour of
RDTreeWidget so that it's not doing anything different by default.
* RDTreeWidget's interface is a bit different, exposing some useful
things like a single selected item and so on.
* We also can't set columns in the Qt Creator UI anymore, so we set them
from code.
baldurk