1.8.1

• dht: fix issue that could cause listen callback to be called after returning false
• dht: reduce connection time for disconnected bootstrap node
• dht: improve performance when used disconnected
• dht: other minor performance improvements
• securedht: improve putSigned performance and network usage
• routing table: fix minor memory leak
• python: added new methods to SockAddr
• added more unit tests
• reduced log verbosity