The usage of the word 'self' to refer to the current iteration became increasingly
confusing with the usual OOP counterpart, in particular because its value can change
in a single expression, independendly of the surrounding object. See previous check
in that uncovered its usage in the fold function.
nested blocks {} and sequences "do .. then .. end" are now merged.
The new sequence "do .. then .. end" has a unique frame.
Implemented support for group number through nesting of sequences.
New tree syntax uses {} instead of [] now that this is available
Removed confusing implicit "new", template now needs to be captured to be available.
Renamed the "template" browsing function to "wrapper".
Change odd syntax is' / has' to is () and has ()
