Useful quick fix for #1363 (SR language not labeled correctly). Now at least it just...

Useful quick fix for #1363 (SR language not labeled correctly). Now at least it just shows sr, rather than also including the user's default language. Specific changes:
* languageHandler.getLanguageDescription: if localeNameToWindowsLCID returns 0, return None instead of going on and trying to use this 0 LCID to fetch a description. It seems that an LCID of 0 actually means the user's default language (in my case it shows English).
* languageHandler.getAvailableLanguages: Only include a description if getLanguageDescription for the locale does not return None. I.e. the label will either be "description, locale" or just "locale".