genini: support multiple compression formats

[Charles Wilson]

Christopher Faylor wrote:
> My email was down today after a catastrophic "simple" upgrade of
> spamassassin which pulled in perl 5.10.1 so I haven't seen the previous
> patch yet but, from the archives, it looks ok to me.

sorry to hear that.

> Thanks for the patch.
> 
> Please check in.

Done.  I have a separate local workaround for another issue, related to
the recent message: support, but I'll raise that in a new thread.

--
Chuck