Do some refactoring. Removes class Troupe. Its fucntions are
splitted between classes Scenario and Robot. Removed classes
DanceDescription an FrameFlow. Their functions are moved to
class Dance. Function Perform from class Director splitted is
splitted in three functions due to its size. Some other
changes mostly in names.
Adds music command which allow to add mp3 files to performance.
Unmusic commands unloads file. Music is playing while robot is
dancing after command start.