Cleanup: removed unused function; also murder instead of call for suicide (delete this)

rtengine/image16.h

@@ -40,8 +40,6 @@ public:
 
     Image16* copy() const;
 
-    Image8* to8() const;
-
     void getStdImage(const ColorTemp &ctemp, int tran, Imagefloat* image, PreviewProps pp) const override;
 
     const char* getType() const override
@@ -67,11 +65,6 @@ public:
         return getEmbeddedProfile();
     }
 
-    int getBitsPerPixel() const override
-    {
-        return 8 * sizeof(unsigned short);
-    }
-
     int saveToFile(const Glib::ustring &fname) const override
     {
         return save(fname);
@@ -97,10 +90,6 @@ public:
         setProgressListener(pl);
     }
 
-    void free() override
-    {
-        delete this;
-    }
     void ExecCMSTransform(cmsHTRANSFORM hTransform);
 
     /* void                 ExecCMSTransform(cmsHTRANSFORM hTransform, const LabImage &labImage, int cx, int cy); */