Support default ansi encoding with winapi backed

[KindDragon]

Please suport ansi encoding for this scenario or at least throw exception

boost::locale::generator gen;
gen.use_ansi_encoding(true);
locale_ = gen("");

It is suprizing when you get UTF-8 in this situation

[Artyom Beilis]

See: http://www.boost.org/doc/libs/1_51_0/libs/locale/doc/html/default_encoding_under_windows.html

Not all backends support ANSI encoding - you can use std backend and it would work if compiler supports one,

also ANSI encoding is really not the way to do localization.