Correctly localized strings

[Michal Svec]

Hi!

The strings program uses isprint function for recognition of printable
characters. This (glibc) function is localized correctly (according to
the locale returns correct result on local characters.

However, it is needed to correctly initialize locales in the strings.
Now, only messages are used (LC_MESSAGES), it is needed to init all
locales (LC_ALL).

And finally, use the isprint function, not isascii, as not all local
characters are ascii.

The (small) patch is attached.

Regards
Michal