Added function stubs to enhance interactivity renamed Song_timer

-Song_timer.py now RIVA_Main.py
-Added select_response() to support more interactive response behaviors
-Added Test_log_updater.py to enable pseudo-auto testing without
requiring Musicglove to be running
-Added _followup as a class variable to User_Stats to enable tracking of
grips needing followup by RIVA_Main.select_response()