The PortMidi queue just holds a pointer to the midi events.
The same Midi events are free()d during WavesMidiBuffer::clear()
which is called at cycle start for every buffer and in the dtor
of the WavesMidiBuffer.
This follows the letter sent from Waves Audio Ltd. to Paul Davis dated February 20th 2014 agreeing to release this code
under the GNU Public License, version 2, with copyright owned by Waves Audio Ltd
