Added a "position" argument.

Added a "position" argument.

2004-02-27  Federico Mena Quintero  <federico@ximian.com>

	* gtk/gtkfilesystem.c (gtk_file_system_insert_bookmark): Added a
	"position" argument.

	* gtk/gtkfilesystem.h (GtkFileSystemError): Added value for
	GTK_FILE_SYSTEM_ERROR_ALREADY_EXISTS.
	(struct _GtkFileSystemIface): Added a "position" argument to the
	::insert_bookmark() method.

	* gtk/gtkfilesystemunix.c (gtk_file_system_unix_insert_bookmark):
	Updated; renamed from gtk_file_system_unix_add_bookmark().  Return
	an error if the path already exists in the bookmarks list.
	(gtk_file_system_unix_remove_bookmark): Return an error if the
	path does not exist in the bookmarks list.

	* gtk/gtkfilechooserdefault.c (shortcuts_add_bookmark_from_path):
	For now, use gtk_file_system_insert_bookmark() with -1 for the
	position.  DnD will come next.