att5

* parser.c parserInternals.c tree.c include/libxml/parser.h
  include/libxml/xmlerror.h: adding namespace checkings
  while making sure they still parse as wellformed documents.
  Add an nsWellFormed status report to the context, and
  provide new appropriate error codes.
* Makefile.am result/namespaces/* test/namespaces/*: add
  specific regression testing for the new namespace support
* test/att5 result/noent/att5 result/att5 result/att5.sax:
  add more coverage for the attribute parsing and normalization
  code.
Daniel