Correction of annoying cracks

Due to the fact that we cut the sound at n seconds and not at the end of the period.

Sidenote : dropped numpy part in sound4python, not happy with it.
Started code for Noel2013

* Arduino code to handle 5 electrodes (5 notes in Jingle Bells)
* TODO : Reuse python code from chorizo to play the music
Flake8...
Started code for Noel2013
Working on code for Noel2013

Started serial handling

TODO : Serial in main loop + args