Make more progress on performance issues, including:

• Fix RPC log filter problems,
• Eliminate read DoS attacks with new statedb snapshots,
• Remove non-Dogechain peers through protocol identification,
• Try something in sentry mode to protect private nodes,
• Quick sync peer selection,
• Properly implemented database batcher,
• Fix memory leak in bootnode connection and other use cases.
• Snapshots feature to reduce I/O compact in multiple call transaction.