The ability to use ^P from within a TTY getlin prompt didn't work with
msg_window:combination: it's a combination (unsurprisingly) of 'full'
and 'single', but hooked_tty_getlin() was treating it like 'full': i.e.
expecting everything to be displayed at once, with doprev_message()
returning only once the user was finished reading. I didn't even know
^P was supposed to be accessible from a getlin prompt until Pat's recent
commit 5120764, because I have always used msg_window:combination -- I
had come up with a system where I'd name a potion thrown at me "xx",
check the previous messages with ^P, and then rename it from the
discoveries list. This will be a lot easier!