Update README.md
AbstractCodeGenerator is not a subclass of NodeVisitor
Fix issue #429 - #printString call #printOn:

All subclasses of Object now implement #printOn:
Removed Object >> printNL and #log:block:
- Fixed Array printing
- Updated printing unit tests
Removed Symbol >> asSuperSelector
Fixes issue #414
Add Pharo-like handy Object >> #putOn: and Stream >> #<< for streaming
Small SequenceableCollection refactoring:

- Only sequenceable collections can be streamed
- Moved some methods to SequenceableCollection
Regression tests for #428.
Fixes #428.