change chan osc range - PLEASE READ

as of now the range is ~32768, either from -16384 to 16383, or 0 to 32767.
it previously was -32768 to 32767 (~65536).

this change was made to better suit chips that only output a positive value.
if you are working on a new chip, update your code and shift right by one if necessary.

src/engine/platform/snes.cpp

@@ -91,7 +91,7 @@ void DivPlatformSNES::acquire(short** buf, size_t len) {
       next=(next*254)/MAX(1,globalVolL+globalVolR);
       if (next<-32768) next=-32768;
       if (next>32767) next=32767;
-      oscBuf[i]->data[oscBuf[i]->needle++]=next;
+      oscBuf[i]->data[oscBuf[i]->needle++]=next>>1;
     }
   }
 }