Support hidden rows cols in print preview.

2000-01-18  Jody Goldberg <jgoldberg@home.com>

	* src/expr.c (eval_expr_real) : Add OPER_UNARY_PLUS.
	(do_expr_decode_tree) : Ditto.
	(expr_dump_tree) : Ditto.

	* src/auto-format.c (do_af_suggest) : Add OPER_UNARY_PLUS.

	* src/parser.y (exp -> + exp): treat as OPER_UNARY_PLUS.

	* src/print-cell.c (print_cell_range) : Ignore hidden rows/cols.