[xml] use of valid.h

[Hisashi T Fujinaka <htodd twofifty com>]

I was fooling around with the code and I tried to include valid.h from
libxml2-2.6.22 on a linux system. But libxml2 includes xmlerror.h, and
then xmlerror.h includes parser.h. parser.h includes valid.h and needs
xmlValidCtxt which is declared after the includes in this circular
dependency.

Do I need to include something before valid.h? Is valid.h not meant to
be used on its own?

Thanks.

--
Hisashi T Fujinaka - htodd twofifty com
BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte