Update to ClipBoard cv/flag handling
See commit message, partly about atomic flags but also making use of condition variable local.
I think this simplifies things a bit, but there might be some other reason to communicate "backwards".
One thing that this changes is that when waiting on condition variable, the old previous version used mutex in DataProcessor. This version uses mutex in ClipBoard.
I'm not sure what the mutex in DataProcessor is for, it mainly seems to be serialising multiple threads?
Edited by Timon Heim