logic on checking timeout per operation is incorrect

    After seeing the IllegalArgumentException in a log, I re-thought through the series of events here.
    
    This flag on the op is known by user threads and the IO thread. Thus it
    is modified in these two different ways:
    
    * operation is created and enqueued
    * OperationFuture is returned
    * .get() is called on OF
     **timed out**
    
    * operation is removed from input queue
    * elapsed time is checked
      **timed out**