queue: chunk & iterator have been moved out to separate source file
queue: tests for chunk_meta & iterator have been added
chunk_meta: check on acked count should be made only in case of increasing acked count
concurrent-pump: static method queue_ack which takes vector of data_array::entry has been added
queue-pull: edited to use new static method queue_ack which takes data_array::entry vector
queue-ack: log_prefix & count must be captured by copy
logger_adapter: add newline character to the end of the message if there is no one