Fixes #62 (possibly): fixed a single instance of a crash when opening the PyMusicLooper window
Closes #63: stop playing when when closing the Add Song and PyMusicLooper windows
Closes #60: added menu buttons for going back to the MSU Details and Track Overview pages
Closes #59: added a "Add and Close" button to the Add Song window
Fixes #62 (possibly): fixed a single instance of a crash when opening the PyMusicLooper window Closes #63: stop playing when when closing the Add Song and PyMusicLooper windows Closes #60: added menu buttons for going back to the MSU Details and Track Overview pages Closes #59: added a "Add and Close" button to the Add Song window