2002-04-04  Morten Welinder  <terra@diku.dk>

	* src/main.c (main): Initialize and shutdown expr class.

	* src/expr.c (gnm_expr_new_constant, gnm_expr_new_funcall)
	(gnm_expr_new_unary, gnm_expr_new_binary, gnm_expr_new_name)
	(gnm_expr_new_cellref, gnm_expr_new_array, gnm_expr_new_set)
	(do_gnm_expr_unref): Conditionally use expression pool.
	(expr_init, expr_shutdown): Setup new expression pool.