After wondering for a moment what on earth "ca- values" were, I looked in Language.php, and presume you are referring to the strings defined inside the "Monobook.js" message. So, how to get them in German?
1) edit your wiki's [[MediaWiki:Monobook.js]] page to include the appropriate translations 2) edit your wiki's LanguageDe.php to include them (this will, I imagine, cause them to appear correctly under 1.4's new user-selectable UI language option, if German is not the main language of the site)
In other words, if it's not there in CVS, it's unlikely that it's there anywhere. Yet.
3) Once you've made the translations, send it in for others to use - I believe attaching it to a new bug at bugzilla.wikimedia.org is the normal procedure right now.
I know this is a long-winded way of saying "do it yourself", but the point is there aren't - and never should be - multiple versions of LanguageDe.php floating around: there's the latest one, and there's out of date ones - and the latest one is usually also out of date compared to the English "master" version.
BTW, I'm not sure what you mean by "free"; I've never heard of anyone threatening to charge, or even restrict (make "unfree"), bits of MediaWiki, so either it exists or it doesn't.