Bug 1068382 - Switch to use multilocale.js for every build
Bug 1115807 - Use <meta> keys in favor of manifest.webapp for localization metadata
Bug 1115807 - Migrate all HTML files from manifest.webapp to <meta> l10n
Bug 1115807 - Update l10n.js to use <meta> for l10n
Bug 1115796 - Update l10n.js to use Langpacks API