None Replacement

[hashenberg]

NOTE:
currently if there are no available speakers (all are playing at other slots), AND current speaker is not null, then automatically current slot is replaced with null.

QUESTION:
If current speaker is already null should we check for replaceWithNoneProbability ? i.e. possibility of selecting new speaker as null again.
or always try replace a null slot with valid speaker?

[hburgund]

As always, I reserve the right to shift after I listen to how this behaves(!), but I think just keeping it with the standard behavior of applying replaceWithNoneProbability is fine. It's ok to have the slot have nothing playing twice in a row. This should be simpler to not have a special case, I presume.