bigname2.xml

- SAX.c tree.c debugXML.c: fixed bogus behaviour when an
  undeclared namespace prefix was used, added a warning.
  Cleaned up support w.r.t. entities, spilling out a warning
  and being pedantic on lookups.
- test/warning/ent9 : added testcase for previous example.
- TODO: updated
- parserInternals.h parser.c: changed the way names are parsed
  now allow infinite size and decrease penalty for normal use
- parser.c: Started a big cleanup/check of the parser code,
  fixed some of the most tortuous entity code, spotted code
  unused anymore
- test/*: added tests for very long names and related nasty
  things.
Daniel