Reissuing getlin() with a different prompt wasn't reliably resizing the
X11 prompt widget. After a lot of hacking away at win/X11/dialogs.c I
eventually tried setting the response portion of the widget first and
got much better results, enough to throw away the tentative changes to
dialogs.c.
There's still a lot of room from improvement but I think it would need
to replace the ghostview prompting instead of trying to massage that.
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