Bug 935877 - Locales with latest version of home page shown

* new LOCALES_WITH_LATEST_HOME constant in base.py
* used in home-b2.html only (home page used by locales)
* activate these locales: 'de', 'el', 'es-AR', 'fr', 'hy-AM', 'is', 'it', 'ko', 'pt-BR', 'sq', 'sv-SE', 'tr', 'zh-TW'