[MonoDevelop] Pad docking area idea

[Levi Bard]

> The downside would be that it's not that easy to see which tab is selected ?
> (I don't need that info because I can distinguish the pads by their content)
>
> .. yes I know vs.net duplicates information too - but I don't think
> that this is a reason to do it as well.

Benefits of having the small bar with the full title:
 * You get to see the full name of the pad, which is rarely true on
the tab, and will become even less true if we add close and undock
buttons as well.
 * It is easier to see which pad is selected. It's pretty easy to
distinguish, for example, the Solution and Unit Tests pads from their
contents;
but the Solution, Classes, Files, and Document Outline pads can all
appear very similar at a glance.