Using HTP merge from other lighting desk results in odd flashes

[jevans3142]

Believed to be when output routine can't take the mutex in time from the input code when the two threads are trying to both read and write the incoming DMX buffer at the same time. Solution will be to double buffer or similar.

[jevans3142]

Using DMXcat tester - seems to be limited to not picking up the first three or four channels only? Difficult to replicate.