Improved version: Threading + play(), stop(), pause(), seek() functions

If you are interested, I would like you to merge with my fork. 

* I made the playback of sounds non-blocking by using python threading library.
* I also added functionality to play(), stop(), pause() and seek() within the wav file (see readme).

Known issues at the moment:

* Only mono sounds are supported (will fix that when I have time)

I am using your code without modifications (if I remember correctly), I just split it up a bit, and wrapped it in class.