Some platforms compile ncurses in such a way that the tinfo library needs to
be separately linked in (e.g. Gentoo).
The tinfo library is a low-level library being used by and bundled with
ncurses.
Adding '-ltinfo' to WINTTYLIB in the hint files was considered the most robust
solution to this problem. This still works on systems with ncurses 5.9.
Using pkg-config was ruled out as the default build of ncurses doesn't install
the necessary files.