concrete5/addon_internationalization — pull request #41 by hissy (2013-10-02 16:04:33+00:00)
Title: rel="alternate" hreflang tag should not exclude language of page itself.

I watched a video below. Google says "hreflang should specify all alternates on eace page, including the page itself", but multilingual add-on does not.

Expanding your site to more languages (about 9:49)
http://www.youtube.com/watch?v=8ce9jv91beQ

https://support.google.com/webmasters/answer/189077

Multilingual sitemap already has alternates of all languages.