[gtkextra] Have *nothing* active in a sheet?

[Al H. <al...@ho...>]

	Adrian, and everybody:

	I have a situation where, under certain conditions, I would like to
have *nothing* active in a sheet.  No cells, no children, nothing. 
After going through the GtkSheet code, I am coming to the conclusion
this is not possible without going under the hood and breaking some
rules.

	Is there a proper/accepted way to accomplish this?  I *really* want to
stay above the published GtkExtra API with this project, and not risk
breaking things by diving underneath it.

	Thanks!

-Al