added default lang of en-US and translations package does the set lang based on subdomain

services/web/app/coffee/infrastructure/Server.coffee

@@ -18,7 +18,7 @@ oneDayInMilliseconds = 86400000
 ReferalConnect = require('../Features/Referal/ReferalConnect')
 RedirectManager = require("./RedirectManager")
 OldAssetProxy = require("./OldAssetProxy")
-translations = require("translations-sharelatex").setup(Settings.subdomainLang)
+translations = require("translations-sharelatex").setup(Settings.i18n)
 
 metrics.mongodb.monitor(Path.resolve(__dirname + "/../../../node_modules/mongojs/node_modules/mongodb"), logger)
 metrics.mongodb.monitor(Path.resolve(__dirname + "/../../../node_modules/mongoose/node_modules/mongodb"), logger)
@@ -76,7 +76,6 @@ app.configure () ->
 	app.use ReferalConnect.use
 	app.use express.methodOverride()
 
-
 expressLocals(app)
 
 app.configure 'production', ->

services/web/config/settings.defaults.coffee

@@ -139,6 +139,13 @@ module.exports =
 		features: defaultFeatures
 	}]
 
+
+	# i18n
+	# ------
+	# 
+	i18n:
+		defaultLng:"en-US"
+
 	# Spelling languages
 	# ------------------
 	#