Create basic gettext infrastructure and French language stub.
First attempt at getting .mo files working with windows (wine).
Add Russian stub translation.
Add more gettext calls.
Add German translation.
Fix compile problem on MinGW and force UTF-8 as encoding.
Allow localization to be enabled/disabled in settings.

This is only the logic to handle the settings, no GUI.
Changing the setting requires a restart as disabling localization simply
skips the call to bindtextdomain() at the application start. Due to the
late initialization, this does prevent some of the early functions to
be localized (e.g. the command line help).