message: don't nullify source when stopped
  fixes
diff: @@ -216,7 +216,6 @@ define(["Tone/core/Tone", "Tone/core/Buffer", "Tone/source/Source", "Tone/source
  Tone.Player.prototype._stop = function(time){
  if (this._source){
  this._source.stop(this.toSeconds(time));
  - this._source = null;
  }
  return this;
  };
  