* Optimize Dns Cache's searching speed and memory size
* Optimize route manager and dns resolver
* Increase server task's performance by reducing some atomic operations
* Increase global performance by removing some singletons
* Always use dns resolver as name service policy when redirecting
* Add WFServer::get_listen_addr() for server started on a random port
* Add server task's push() interface
* Optimize poller speed and memory occupying
* Optimize URI parser, more than 50% faster
* Optimize http implementation
* Refactor encode stream. This will improve the performance of Redis and Kafka clients
* Optimize SSL write. Improve the performance of HTTPS client and server a lot
* Optimize weighted-random upstream policy to solve some recovering problem
* Update Cmake files to support more platforms. Build both static and dynamic libs
* Optimize  upstream with consistent hash. Allow adding server with weight
* Improve http protocol compatibility of http client task
* Improve bazel building

* Fix service governance's ref count bug
* Fix mysql sequence id bug when retrying big request
* Fix VNSWRR upstream bug
* Fix dns client bug when host name has trailing dot
* Fix URL parser fatal bug
* Fix crash when resolv.conf is empty
* Fix MySQL transaction checking
* Fix MySQL client crash on incomplete result sets
* Fix SSL wrapper problem on TLS 1.3 handshaking
* Make UpstreamManager::upstream_delete() safe when the upstream is still in use
* Fix the SSL delaying problem on Nagle's algorithm
* Fix bug that cannot use the port in URL when using upstream