allow to give -1 for undefined length in lookups first round of work on

* dict.c: allow to give -1 for undefined length in lookups
* include/libxml/parser.h parser.c parserInternals.c testSAX.c:
  first round of work on the new SAX2 interfaces, the API
  will change but commiting before changing for historical
  reference.
Daniel
6 files changed