release of libxml2 2.6.28 patch from Dagfinn I. Mannsåker for idness of

* doc/* configure.in NEWS: release of libxml2 2.6.28
* valid.c: patch from Dagfinn I. Mannsåker for idness of name
  in HTML, c.f. bug #305885.
Daniel

svn path=/trunk/; revision=3638
23 files changed