Fix most of the compile warnings I get on Linux (but not the Audacity Logo

xpm stuff or a few things in FFMPEG export)

src/NoteTrack.cpp

@@ -78,7 +78,7 @@ Track *NoteTrack::Duplicate()
    if (mSeq) {
       assert(!mSerializationBuffer);
       // serialize from this to duplicate's mSerializationBuffer
-      mSeq->serialize(&duplicate->mSerializationBuffer, 
+      mSeq->serialize((void**)&duplicate->mSerializationBuffer, 
                       &duplicate->mSerializationLength);
    } else if (mSerializationBuffer) {
       assert(!mSeq);