mixer simple basic abstraction - added python binding

reasons:
- rapid development
- class-like code structure
- more readable code
features:
- hcontrol binding is managed from python (opportunity to create
  virtual mixer without driver or join multiple cards to behave as one)

src/mixer/simple.c

@@ -38,7 +38,6 @@
 #include <math.h>
 #include "mixer_local.h"
 #include "mixer_simple.h"
-#include "alisp.h"
 
 /**
  * \brief Register mixer simple element class