Joachim - in the event that you ever return to updating xindy, please get the latest TeX Live version. There have been further fixes related to Mac .mem files and --version, among other things.
You can get the TL version from the web:
http://tug.org/svn/texlive/trunk/Build/source/utils/xindy/xindy-src/user-commands/xindy.in
A better description of the changes is in the upper-level ChangeLog:
http://tug.org/svn/texlive/trunk/Build/source/utils/xindy/ChangeLog
If and when you do come back to it, maybe we can reconcile our use of $Keywords$, like you use only $Id$ and TL uses only $Revision$, or some such. I wanted to incorporate the TL revision number into the --version output, since the reality is that that is what is changing at the moment ...
Thanks. -k
I should have mentioned: other files besides xindy.in have had fixes: markup.lsp, makeindex.xdy, make-inp-rules.pl, documentation files, and no doubt others.
(And unfortunately our TLpatches/ subdirectory has not been kept perfectly up to date, so don't rely on it.)