Patch to get current mainline to compile on RH6.2

[Dave Peticolas]

Derek Atkins writes:
> Hi,
> 
> I needed the following patch to get the CVS mainline to compile
> on RH6.2 using libxml-devel-1.8.6-2.  The problem is the apparent
> lack of an xmlRootNode member of the xmlDocPtr object.  At least
> in version 1.8.6, that structure member is called 'root', not
> 'xmlRootNode'.

The development version requires either libxml-1.8.8 or libxml-2.1.x.
Earlier versions of libxml are incompatible with libxml-2.1.x.

dave