Issues with recent utf8 patch

[Rafał Mużyło]

It seems that the problem comes from the way ncurses move() works. If I
understand it correctly, if move range is outside (0..screen  width) /
(0..screen height) it moves to the previous/next column/line. When I changed
terminal size to 80x20, I got some really silly results when I've gone
up and down File menu several times. Slang variant at least paints it
correctly, though if menu is longer than the term, you can select an
option you don't see. Of course, I don't now pretty much anything about
ncurses, but some bounds checking (no move() outside screen) might help.