- Supported languages now all centralized.

Now the flow for adding a new language is just:
1.Add a new language entry to `res/common/lang/langs.json`.

And for translating it's just:
1. Run `gulp translate` (extracts all the strings).
2. Open `/res/common/lang/po/stf.pot` in PoEdit and translate.
3. Run `gulp translate` again (creates a json based on the new `po` file).

res/app/settings/language/language.jade

@@ -5,4 +5,4 @@
   .widget-content.padded
     .form-horizontal
       .form-group
-        select.form-control(ng-model='language', ng-options='l.code as l.name for l in supportedLanguages')
+        select.form-control(ng-model='language', ng-options='key as value for (key, value) in supportedLanguages')