* gdbtk.tcl (debug_interface): New global, use to aid debugging.

	* gdbtk.tcl (debug_interface): New global, use to aid debugging.
	(insert_breakpoint_tag, delete_breakpoint_tag): Fix range.
	(file_popup_menu): Delete, never used.
	(listing_window_popup): Rename from listing_window_button_1,
	remove breakpoint toggling code.
	(toggle_breakpoint): New procedure.
	(create_file_win): Bind popup menu to button 2, toggle breakpoints
 	with button 1 in breakpoint area, add display of tagged areas if
 	debugging on.