I have renamed `pack!` and `unpack!` to `pack-to` and `unpack-from`, following the advice about not using the exclamation mark suffix with side effects regarding ports. I have also changed the order of arguments so the first argument to `pack-to` is the port and the rest is an arbitrary number of objects to pack.
(pack-to (current-output-port) 2 3 "hello")
I think this also rolls better off the tongue: pack to the current output port
2, 3 and "hello".
