BenderTutor: add MakeB_1.py, MakeB_2.py and MakeB_3.py examples
BenderTutor: add MakeB_1.py, MakeB_2.py and MakeB_3.py examples, showing (together with MakeB.py) four different ways to configure Bender algorithm, and in particular the ways to insert Bender-algorithms into Selection framework