Removed undefined clear() functions in FM, Resonate, Simple, and Sampler classes; a few documentation updates in preparation for 4.5.0 release.

include/Simple.h

@@ -41,9 +41,6 @@ class Simple : public Instrmnt
   //! Class destructor.
   ~Simple( void );
 
-  //! Clear internal states.
-  void clear( void );
-
   //! Set instrument parameters for a particular frequency.
   void setFrequency( StkFloat frequency );