- syntaxtree.py: transformation_factory decorator for processing table functions; further type annotations

- can use operators "+" (Sequence) and "|" (Alternative) for constructing parsers in Python; better testing suppoer

- example MLW extended by adding rudimentary testcases

syntaxtree, class Node: XML-output now puts tags and content of the innermost node on one line for better readability

- virtualized Parser.__class__.__name__ by introducing Parser.ptype (which by default is set to Parser.__class__.__name__)
- removed all isinstance(node, ...) statements from ebnf.EBNFCompiler, because this does not work with mock trees which are be needed for testing.

- better syntaxtree.mock_syntax_tree() generation: Can now read actual ASTs in S-expression form. Useful for testing of AST-transformation or -validation as long as these do not call isinstance() on any parser.

- added `start_parser` parameter to `GrammarBase.parse` in order to allow fine grained testing of ENBF syntax descriptions;
- added `dsl.suite_outdated`
- further corrections