Extract saxon.jar from the distfile for the textproc/saxon port into
the thirdparty build directory for the scilab port. This allows the
removal of the textproc/saxon build dependency from the scilab port so
that scilab can be built on a host that has apache-openoffice-3.4.*
installed. The latter port has a run dependency on textproc/saxon-devel,
which conflicts with textproc/saxon.
Approved by: Rob Farmer <rfarmer AT predatorlabs.net> (maintainer)