[Implemented] Commands to Clear/Close Debug Display

[oldefoxx]

I'm using Debug to track API return values at different points in my program.
That way I can say what it is I am returning, then see what the returned
value is. Works fine, but It would be helpful if I can more control over the
Debug Window itself - clearing of previous results, or closing it when I am
past the point of using it to display pertenant information.

[Kale]

This would be great! Clearing the Debug Output window would be very helpful

[dmoc]

In the mean time DbgView is pretty useful.