seprate window management component

[Bill Spitzak]

Michal Suchanek wrote:

> Still the clients should not know about the windows of other clients
> so they would not know how their windows stack and not knowing that
> they can't really decide it either.

I don't think the clients will know about any windows other than a few 
ids that the compositor tells them about. By default they can only put 
windows immediatly above or below another window they own, or put them 
at the top/bottom of the stack by passing None for the other window.

> They should be able to decide relative stacking of their windows so if
> a document window is raised, the client is notified of that, and the
> client responds by raising its toolbar windows it might work.

The client needs to be able to do the raise, it can't just respond to 
the raise from the compositor. This is because it may want to raise or 
map other windows above the raised one, and this must either be done 
first, or atomically with, the raise of the main window. If this is not 
done, the floating windows will blink which is unacceptable.