2001-10-29  Jody Goldberg <jgoldberg@home.com>

	* src/parser.y : add support for referencing names in other workbooks.

	* src/expr.c (expr_tree_new_name) : take an optional sheet and
	  workbook as scoping info.
	(expr_eval_real) : handle inactive names.
	(do_expr_tree_to_string) : improve scoping.
	(expr_rewrite) : handle inactives and scope changes.

	* src/expr-name.c (expr_name_lookup) : add the notion of active and a
	  ref count so that we can do a delayed destruction and invalidation.
	(expr_name_add) : make it clearer that the return is not meant
	  to be freed.
	(expr_name_create) : don't free the result of expr_name_lookup.
	(expr_name_ref) : generalize.
	(expr_name_unref) : ditto.
	(expr_name_remove) : deactivate the name.