* tkcon.tcl (DeleteTab, Destroy): improve the 'exit' handling so

	* tkcon.tcl (DeleteTab, Destroy): improve the 'exit' handling so
	that 'exit' in the first created tab doesn't do a full exit.
	'exit' in the last tab of the first created console still exits
	tkcon, fixing that requires a rearch of the console
	creation/management.
	(InitTab): Have the <Configure> binding only fire for the root
	window, not for each tab.
	(GotoTab): Keep tabs around - just raise/lower instead of grid
	remove/add.  break on Next/Prev Tab binding to get focus right.
	(Prompt): return if console w doesn't exist