- Ideally Queues must outlive the threads using them, but wasn't done so. Yes, std::shared_ptr them!
- Now queues are always valid in the context of the threads using them.
- No longer need tedious queues deallocation by the original owner.
- Misc cleanups.
Besides deadlocks, a thread can in theory get stuck in a blocking pop(),
not seeing the stopping flag in particular. So assure liveness by making all
pop() timed pop.
- Clear up DemodulatorInstance garbage collection, only do it in a single thread (AppFrame::OnIdle)
- Add a specific mutex lock for the list of deleted demodulators,
- Add a specific lock to control DemodulatorInstance thread lifetimes, protecting IsTerminated() of concurrent join and delete
BLOCKING_QUEUE: Replaced ThreadQueue usage by ThreadBlockingQueue usage
BLOCKING_QUEUE: instrument all push() with timeouts, showed some call have to be non-blocking...
BLOCKING_QUEUE: tuned push()/try_push()