#65 pseudo lang: interwiki link as in MediaWiki

[Reini Urban]

Provide automatically pseudo interwiki entries for the
current page in alternate languages. (as the magic
Upload: link)

en: HomePage:
[de:StartSeite], [fr:PageAccueil]

Maybe:
provide a method to list those special links, like
altLanguageLinks($pagename)

provide a plugin (or syntax extension) method to list
automatically all registered alternate language
versions of a page.