1. Add a new field to chain:ataChain to include pending blocks that have been accumulated but not paired yet:
2. Consider provide a separate function allowing PeerManager fetched the expired pending blocks. This is mainly for the logging and testing purpose. The time out duration is suggested to be 2 mins.
3. Add a new method to append a pair of valid blocks to the chain:
4. The add_vote method defined in shall append the vote to block which could exists in the pending_blocks or in the chain.