cleanup: remove debug writeln() that's not needed any more.
Fixes issue highlighted by lm-flow demo. Form Resize didn't trigger LM's DoLayout()
new: adds a new gui example showing usage of Flow Layout Manager.
feat(layout): Implement wrapping in FlowLayout and add Iterator
docs: Mark layout manager Phase 1 as complete
cleanup: Removes TLayoutPair that is now unused.
docs: layout manager analysis and implementation plan
refactor: Lets encapsulate the internal storage type of layout managers. Iterator to the rescue