pgsql: Attached is a patch that adds the function

Log Message:
-----------
Attached is a patch that adds the function xml_encode_special_chars to
the xml2 contrib module. It's against 8.0beta4. It's intended for
commit.

Markus Bertheau <twanger@bluetwanger.de>

Modified Files:
--------------
pgsql/contrib/xml2:
pgxml.sql.in (r1.2 -> r1.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/xml2/pgxml.sql.in.diff?r1=1.2&amp;r2=1.3)
xpath.c (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/xml2/xpath.c.diff?r1=1.4&amp;r2=1.5)