Log Message:
Update SDL2_mixer to 2.0.1:

2.0.1:
Sam Lantinga - Tue Jul  7 11:40:33 PDT 2015
 * Added support for 'smpl' format loop points in music WAV files
Sam Lantinga - Sat Aug 23 10:57:26 2014
 * Fixed floating point exception in Mix_Volume()
David Ludwig - Mon Apr 14 22:15:36 2014
 * Added support for building for Windows RT and Windows Phone
Isaac Burns - Sun Sep 15 21:50:27 PDT 2013
 * Added support for loading MP3 files as sound chunks