fix wavesbackend midi timing
fix dup free in waves/midi:

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.
add support for OSX 10.9 clang's lldb  (there's no gdb on 10.9)