[pca] outdated patchdiag.xref

[Martin Paul]

The default URL used by pca to download the patchdiag.xref file 
currently provides an outdated version of the file (Oct/19/09). There is 
an alternative URL - which requires wget with HTTPS support - which has 
the correct file (Oct/21/09).

I've now made a change to the development release of pca to use the 
alternative URL if a wget with HTTPS is available. You can get it from:

   http://www.par.univie.ac.at/solaris/pca/installation.html

The new URL delivers the xref file via Akamai (as it's already done for 
patches and patch READMEs), and has the extra advantage that it's faster 
(3 vs 10 seconds download time for me).

Nevertheless I hope that the correct file will soon be delivered via the 
old URL again, too, as this will continue to be used when there's a wget 
without HTTPS support.

Martin.