Fix completion so it doesn't pop up for every character in a URI
	hostname:

	* gtk/gtkfilechooser.h (GtkFileChooserError): Add a
	GTK_FILE_CHOOSER_ERROR_INCOMPLETE_HOSTNAME.

	* gtk/gtkfilesystem.c (_gtk_file_system_parse): Return an
	"incomplete hostname" error if the user has not typed a full
	hostname yet in an URI.

	* gtk/gtkfilechooserentry.c (append_common_prefix): If we get an
	incomplete hostname, just don't pop up an error, since that is a
	transient state and the user doesn't need to be notified about it.
	(refresh_current_folder_and_file_part): Don't revert to showing
	the base folder if we have an incomplete hostname.
	(reload_current_folder): Handle the passed folder being NULL, even
	if we must force a reload.  Also, reload the folder if we didn't
	have a cancellable for it (i.e. we hadn't started to load it
	before).

Signed-off-by: Federico Mena Quintero <federico@novell.com>

svn path=/trunk/; revision=22157