One old drawback now has a new look. Before, we loaded definitions in
order, so global definitions had to exist before other global
definitions that used them. See window and grid in life.tlv. Now we load
definitions in reverse order, so initialization needs to change. Worse,
if we update window, we need to edit grid just to fix the order.
This implies that we can't yet optimize away bindings where there are no
new changes.
