Added support for functions referencing themselves.
Added local scope indication in the viewer (showing local/nested classes and
functions).
Added tests of nested classes and functions.
1l=[(0,10),(10,20)] 2y=23 3fora,binl: 4foriina,b: 5x=i 6else:# NOTE: Need to support StopIteration! 7x=y 8else: 9a=b