[xml] libxml3

["Peter Jacobi" <pj walter-graphtek com>]

Hey, has libxml3 requirements gathering time started?

One thing I'll like to see (and will see after it when it's
really time for libmxl3):

"visiting" as an alternative to "concatening"

For functions which assemble a new (and newly allocated)
character buffer by concatening several pieces (and probably
reallocating in this process), I would like to have an 
alternative by giving a visitor callback as parameter,
which gets called for each fragment.

Regards,
Peter Jacobi