moved char/string syntax to Tools/string_syntax.ML; HOLogic cleanup;
moved char/string syntax to Tools/string_syntax.ML;
HOLogic cleanup;

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