Fix JLocale Chooser - to select GUI language
The JLocaleChooser did not work under MS Windows platform or if directory containing i18n data was not found.
The JLocaleChooser has been modified to handle correctly URL (change file separator to '\') and only display current, if the i18n directory is not found.
There is still a bug with de_CH flag, which do not display.
In the future, only available locale will be displayed/selecteable.