The default UI language returned by GetUserDefaultUILanguage does not
necessarily reflect what the user really wants. E. g., the system could
be en_US, but the desired language is en_CA, without having a CA langpack
installed.
Changing the settings under "Languages" and changing the keyboard layout
is only affecting the so-called "Input language", while what's returned
by GetUserDefaultUILanguage is the "Display language". Changing the
latter requires installing MUI langpacks.
Thus, we introduce a way to fetch the "Input language" using the -i or
--input option.
Also clean up documentation of locale(1).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
c02ac89f28