Removed non-libsndfile sound IO files. Add natben.c.
Removed non-libsndfile sound IO files. Add natben.c.

csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound