* dict.c include/libxml/dict.h Makefile.am include/libxml/Makefile.am:
  new dictionary module to keep a single instance of the names used
  by the parser
* DOCBparser.c HTMLparser.c parser.c parserInternals.c valid.c:
  switched all parsers to use the dictionary internally
* include/libxml/HTMLparser.h include/libxml/parser.h
  include/libxml/parserInternals.h include/libxml/valid.h:
  Some of the interfaces changed as a result to receive or return
  "const xmlChar *" instead of "xmlChar *", this is either
  insignificant from an user point of view or when the returning
  value changed, those function are really parser internal methods
  that no user code should really change
* doc/libxml2-api.xml doc/html/*: the API interface changed and
  the docs were regenerated
Daniel