Note some cross-compilers might not install the ncurses config scripts
and only the pkg-config files, but at least the atari SDK from NS does.
For others it might be required to check for the .pc files first.
CFLAGS and LDFLAGS may be passed in by an upstream build system. we
want to make sure we absolutely add our dependency flags otherwise
stuff like hardening flags will break the build
Closes: #29
previous Makefile changes didn't actually work for pkg-config. they
were taken from the Debian package, which operated differently.
furthermore, the ncurses5-config lines were incorrect: they were using
both ncursesw and ncurses and would fail if --libdir was
empty. instead, we use the more proper --cflags and --libs that all do
the right thing.
this should, arguably, only be done with pkg-config, but i didn't want
to introduce an additional dependency.
See: #38
this creates warnings in Debian, as there are checks to see if we use proper hardening flags, for example.
besides, we *almost* show all the tags in the compile rule, might as well not silence it