* testReader.c xmlreader.c valid.c include/libxml/tree.h
  include/libxml/valid.h include/libxml/xmlreader.h: working on
  DTD validation on top of xml reader interfaces. Allows to
  validate arbitrary large instances. This required some extensions
  to the valid module interface and augmenting the size of xmlID
  and xmlRef structs a bit.
* uri.c xmlregexp.c: simple cleanup.
Daniel