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/n163.cpp

@@ -118,7 +118,7 @@ void DivPlatformN163::acquire(short** buf, size_t len) {
     buf[0][i]=out;
 
     if (n163.voice_cycle()==0x78) for (int i=0; i<8; i++) {
-      oscBuf[i]->data[oscBuf[i]->needle++]=n163.voice_out(i)<<7;
+      oscBuf[i]->data[oscBuf[i]->needle++]=n163.voice_out(i)<<6;
     }
 
     // command queue