silverstripe/silverstripe-translatable — pull request #133 by Ekman (2013-08-18 16:45:10+00:00)
Title: Links in head will now include translated versions of each page including itself

Changes to reflect missing information in the head. Quote from Googles website (source below):
"If you have multiple language versions of a URL, each language page in the set must use rel="alternate" hreflang="x" to identify all language versions including itself."

https://support.google.com/webmasters/answegir/2620865?hl=en&ref_topic=2370587