Implemented tracking of VPU frames without dynamic data structures such as queues.
It tries to remove as much internal states as possible. Tested and working. Tracking
of bound frames is done in Decode and bases its check on the maximum dequeued frame
number. All queued VPU frames with lower numbers are going to be released. First
working version since commit 11561847cdd3001c8975cd27320591098cc1473e.