locale in ruby

Hello

I tried to make the curses extension work with utf-8. It is possible
but it requires setting locale properly which Ruby currently does not
do. It also requires ncursesw but these are typically available on
systems that do multibyte terminal IO.

Generally Ruby should be able to work with multiple encodings so it
might seem that setting the locale does not make sense. However, the
locale variables are used to set the default IO encoding. Some
libraries like ncurses use the locale information to determine which
characters are printable and won't work without a call to setlocale.
This makes sense as the library is used for UI which should respect
the locale settings.

It is possible to do the call in the extension itself but this is the
wrong place. Multiple extensions could stomp on each other when
setting the locale. If the libruby in linked to a program other than
ruby and the extension is loaded it may break the settings of the
program.

So it appears that the right place would be to set the locale during
the interpreter's initialization from the environment, and allow other
applications using ruby to deal with locale themselves. Some libc
routines might behave differently when locale is set, there is at
least one comment about setlocale in the ruby source.

However, not setting the locale only hides improper use of these
routines. These should be only used for presenting information to the
user - the UI. So the only place for such routines might be the
inspect method if they should be used at all. Since ruby extensions
and applications using libruby might use setlocale it is a bug if some
parts of ruby depend on the locale to be left at POSIX for correct
operation.

Thanks

Michal