snapshot inside poly~ don't mute?

When you mute an instance in a poly~ it turns off the signal
processing, but it does not turn off the message-passing activities of
the main and scheduler threads. The only thing snapshot~
signal-processing code does is store the most recent value in a
variable so that when the object is asked to output a value, either by
a bang or the internal clock, it accessess the variable. Turning off
the signal processing simply freezes the most recent value.

The code for number~ is very similar except that there's a filter in
the number output method that prevents the same number from being
output twice in a row. In other words if the internal stored value is
unchanged since the last output, nothing is output until a change
occurs.

There's one other very important difference between these similar
capabilities of snapshot~ and number~: when internally clocked,
snapshot~ outputs the data in the scheduler thread. number~ defers
the output to the main thread.

Ben