TransferQueueBundler calls BlockingQueue.add() to add a message. When the queue is full, this blocks the caller until there's space in the queue, or the bundler is stopped.
Sometime, dropping a message might be better, to prevent many threads being blocked on the full queue. Messages will be retransmitted anyway.
Therefore add an option to TransferQueueBundler to drop messages (BlockingQueue.offer() instead of BlockingQueue.add()) when the queue is full.
This should also be added to TP as an attribute.