ipt_parse now remembers rule numbers. Wrote iter_cts()
iter_cts handlers probably don't need extra arguments. Remove that parameter. If we want it to perform differently, just write another function that behaves differently.
Make iter_cts more useful by letting users return stuff if they want.
Still fiddling with iter_cts; split into two functions
stdout_display_ct is now compatible with the iter_cts functions.