[PATCH] math:random() missing its seed

Hey,

I recently noticed that the current implementation of math:random()
repeatedly always produces the same random numbers.

After looking into the code and digging up a few messages from 2008
(http://comments.gmane.org/gmane.comp.gnome.lib.xml.general/13910) I
realised that the current implementation is missing its seed.

My modifications only apply to xsltproc itself. I figured that for now
software linking to libxslt may either already have run srand() itself
or may be required to do so in order to use the lib.

I also absolutely understand the need for a deterministic and
reproducible seed, so besides running srand(time(NULL)) once during
program startup I implemented a command line parameter --seed-rand
with wich the seed can be overridden manually.

The patch can be found at
https://github.com/nils-werner/libxslt/compare/master...seedrand.patch

Regards,
Nils Werner