* xmllint.c doc/xmllint.xml: added --nonet option
* doc/Makefile.am: fixing #112803 by adding --nonet when calling
  xsltproc or xmllint
* doc/xmllint.xml doc/xmllint.1: also added --schema doc and
  rebuilt
* HTMLparser.c: cleaned up the HTML parser context build when
  using an URL
Daniel