extension functions support

[Hakob Zarobyan]

        Hi All,
As far as i understand from previous discussions in the mailing list, this
implementation supports extension function
(http://www.w3.org/TR/1999/REC-xslt-19991116,     14.2 Extension Functions).
However, i did not find any information/instruction which provide me with
the tips, how to add new extension functions. I will appreciate, if you
feedback me on this point.
Thanks.
regards,
Hakob