Sound via Paul's SoundSystem + WAV and MP3 codec

This commit introduces a whole lot of classes to JangoDare, with the
reason that there's finally sound in this engine!
It is powered by Paulscode's SoundSystem (http://paulscode.com/), which
means it should be very reliable.
There are currently 2 codecs bundled, one is WAV (also by Paul), the
other one is MP3 (by fireandfuel).
You don't have to worry about any type of complicated source management
as there's a class called SoundManager that handles all that for you.
Every Game instance has one by default.