HTML Meta information about XWiki documents are incorrect in the case of translations

In htmlheader.vm you have the following code

#xwikiDataAttribute('version', $doc.version)

#xwikiDataAttribute('rest-url', $[services.rest|http://services.rest/].url($doc.documentReference))

In the case of a translated document it should be $tdoc.version.

Also the rest url corresponds to the default document and not the translation.

Also it would be nice to have language information about the document