Add a ThreadedBaseClass that ProcessorBase inherit from.
It allows the computation of the ProcessorBase::process(...) to be performed in a separated thread. Threads aren't instantiated/killed but instead are put to sleep waiting for new CaptureBase.
ThreadedBaseClass API is rather simple :
Constructor with argument max_frequency allowing the user to set guess what, a max frequency at which the processor operates.
run() to start the thread and so the processor.
stop() allows to stop the thread and so the processor.
isRunning() let the user know if the processor is running or not.
