HEADS UP: ncurses wide character support

[Rong-en Fan]

Hi,

Now we have ncurses 5.6 and wide character support in
6.x after __FreeBSD_version 602107. If your port supports
it, you may want to enable it for better unicode support.

For example, mutt's WITH_NCURSES_PORT knob may be
adjusted to consider this fact :-)

Regards,
Rong-En Fan