[xslt] Compiling libxslt (and libxml2) on OS X 10.1.4

[Michael Urban <urban panix com>]

I had some problems with these, but managed through.  Perhaps
my experiences are of interest.

The versions: libxml2-2.4.18            libxslt-1.0.14

Compiling libxml2: 

It sufficed to change allow_undefined_flag  in the darwin* clause
to "-undefined error".

libxslt was tricker.  My first problem was that it using the
libxml2 source directory via --with-lib-xml-src=   failed.
There were two problems with the invocation of xml2-config
in this case: first, the xml2-config script was mode 644
and so could not be executed directly; second, it does not
have a "print" argument as the configure script attempted.

The same trick with allow_undefined_flag failed, but per an entry
on the Perl-XML mailing list (located via Google) at
http://archive.davin.ottawa.on.ca/axdtk/2001-11/msg00108.phtml I
instead changed the darwin clause to

  allow_undefined_flag='-undefined suppress -flat_namespace' 

This allowed the build to succeed.  

I'm sorry I didn't go through the "usual channels", but hope
that this helps improve the next releases.

	Mike