Forecastfox l10n

Fully localized version of Forecastfox (created by Jon Stritar and Richard Klein).
This isn't the official version of Forecastfox! Go to https://addons.mozilla.org/firefox/398/ instead if you want it.
Everything is translated, including the forecasts (more than 170 (+ the variations)), day names and other informations. The forecasts aren't trimmed down for the translations, unlike in the original Forecastfox extension.