Eclipse Mosquitto™ 1.6.7

Broker

• Add workaround for working with libwebsockets 3.2.0.
• Fix potential crash when reloading config. Closes #1424, #1425.

Client library

• Don't use `/` in autogenerated client ids, to avoid confusing with topics.
• Fix `mosquitto_max_inflight_messages_set()` and `mosquitto_int_option(...,  MOSQ_OPT_*_MAX, ...)` behaviour. Closes #1417.
• Fix regression on use of `mosquitto_connect_async()` not working. Closes #1415 and #1422.

Clients

• mosquitto_sub: Fix `-E` incorrectly not working unless `-d` was also specified. Closes #1418.
• Updated documentation around automatic client ids.