[GRASSGUI] can't dock map display with AUI

[Glynn Clements]

Michael Barton wrote:

> It looks like we can't doc the map display using AUI unless we redo the main
> window as a wx.Window or wx.Panel. I don't know if that would be a real
> problem to do or not.

For a docking UI, you normally need at least one top-level window
which cannot itself be docked. Children can either be docked into this
window or undocked as separate top-level windows. If you undock
everything, you end up with an empty[1] main window whose only purpose
is to sit around in case you want to re-dock the children.

[1] Or almost empty. There may be some components which can't be
undocked, e.g. the menu bar.

-- 
Glynn Clements <glynn at gclements.plus.com>