added type theory: generic theory contexts with unique identity,   arbitrarily typed data, linear and graph development -- a complete   rewrite of code that used to be spread over in sign.ML, theory.ML,   theory_data.ML, pure_thy.ML;
added type theory: generic theory contexts with unique identity,
  arbitrarily typed data, linear and graph development -- a complete
  rewrite of code that used to be spread over in sign.ML, theory.ML,
  theory_data.ML, pure_thy.ML;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle