* Fix issue where it would automatically scroll when collapsing panels.
* Fix panel dragging not taking zoom level into account.
* Fix enum menu having too small default width in headers.
* Fix tooltips not showing shortcuts etc. if there was not tooltip
defined for the button.
* Fix some refresh issues with color ramps.
* Add a bit more space between columns in the layout engine.
* Make scrollers darker so they are less distracting, and highlight
instead of reverse shading when dragging.