Audiolet = function(sampleRate, numberOfChannels, bufferSize) {
    this.output = new AudioletDestination(this, sampleRate,
                                          numberOfChannels, bufferSize);
}
The base audiolet object.  Contains an output node which pulls data from
connected nodes.

@constructor
@param {Number} [sampleRate=44100] The sample rate to run at.
@param {Number} [numberOfChannels=2] The number of output channels.
@param {Number} [bufferSize] Block size.  If undefined uses a sane default.