Support X.509 certificate based authentication (#1388)

Add proxy_protocol, proxy_protocol_timeout options for ws/wss listener.

Cluster discovery etcd nodes key must be created manually. (#1402)

Will read an incorrect password at the last line of emq_auth_username.conf (#1372)

How can I use SSL/TLS certificate based client authentication? (#794)

esockd

Improve the parser of proxy protocol v2.

Add ‘send_timeout’, ‘send_timeout_close’ options.

Rename esockd_transport:port_command/2 function to async_send/2.

Add test case for esockd_transport:async_send/2 function.

Add esockd_transport:peer_cert_subject/1, peer_cert_common_name/1 functions.

Fixed the issue that Cannot connect to MySQL 5.7 (#67).

emq-relx

Fix mergeconf/3 appending line break error. (#152)

Fix crash in emq_sn_gateway:transform() function which handles SUBACK. (#57)

Define macro SN_RC_MQTT_FAILURE. (#59)

emq-web-hook

Filter auth_failure client for disconnected hook. (#30)