added avoid_walls.py, dance_sing_menu.py, light.py

light.py - this program makes Scribbler to take X number of pictures and
average light readings passed down as a parameter and create a webpage
with a table that has all these pictures and values in a table format

avoid_walls.py - Scribbler will move inside an arena without hitting
walls for some time and then make a celebratory dance and sound

dance_sing_menu - gives a menu to a user with a choice of a song and 3
dance moves. Upon completion, asks it again until the user enters 'quit'