Add lang-selection string to all locales

In gh-110 lang-selection string was added only to ru-RU locale. This resulted in erroneous (Russian) string being shown for other languages, when either:
 - User selected "ru-RU" from select box;
 - User had "ru-RU" locale set-up in browser and opened any asknot page, including visits from permalinks.

Solution is quite straightforward - include lang-selection string for all locales.

As I am obviously not proficient in all changed languages, translations were taken from:
  - http://transvision.mozfr.org/string/?entity=browser/chrome/browser/preferences/languages.dtd:languages.customize.selectLanguage.label&repo=central
  - http://transvision.mozfr.org/string/?entity=mobile/android/chrome/localepicker.properties:chooseLanguage&repo=central

For Asian/Arabic/non-Latin script locales there is sadly no translation available, and it is left to corresponding translators to fix this one up.

Closes gh-71
Fixes gh-111