4.6.0-pre1: cant disable ncurses

[Pavel Roskin]

Hello, Moritz!

> b) --without-ncurses --with-included-slang
> 
> > Don't use "--without-ncurses", it makes no sence.
> 
> Any configure option --with-foobar must make sense as --without-foobar
> (= --with-foobar=no), e.g. if you're not sure about the defaults.

On the other hand, you should not override the defaults unless necessary.
Ok, I'll do it for ncurses, but I'm not going to audit every option.

> are you trying to say that "--with-ncurses" is _only_ meant for
> pointing to ncurses' location? Okay, I stand corrected, but I find it
> unclear. (./configure still always says "Optional Packages:
>   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]

That's the real bug!  Those brackets were in configure.in, but Autoconf 
ate them.  Fixed now.

-- 
Regards,
Pavel Roskin