Change the '|'/#perminv final positioning for X11 to be the same
as for curses: finishing with <escape> leaves the current view,
with <return> resets to unscrolled.
Actually getting ESC and RET to the right place wasn't trivial;
down the rabbit hole and out the other side. Using yn_function()
to get the #perminv keystrokes is less than ideal. (curses also
started that way but switched to raw character input for this.)