Dockable toolbar

[mottosso]

Goal

Facilitate greater customisation.

Motivation

The top-most toolbar is a plain QToolbar that has been locked to only appear in its default position. But it would be trivial to make it detachable, and move to the bottom. Moving it to one side is a little more work, as we'll need to re-arrange the layout, but it's possible and could help save precious screen space.

Implementation

Unlock toolbar and facilitate docking to one side.