Add warning re lack of ACK when no handler

Merge pull request #578 from shivamkm07/master

Support for AutoAckOff - Enables users to disable automatic ACK for incoming messages. Users MUST call `m.Ack()` themselves if this is set yo `true`. Please remember that the MQTT standard does not require the broker to sesend messages except when the connection is re-established.

Update license to meet pkg.go.dev requirements

pkg.go.dev was not displaying docs due to license

Merge pull request #590 from ptsneves/pneves-disconnect-workaround

client.go Remove Disconnect()'s wait on `c.commsStopped` (preventing potential race)

Merge pull request #512 from ChIoT-Tech/master

Resolve rare deadlock caused by loss of connection (in particular circumstances)

Merge pull request #502 from ChIoT-Tech/master

Handle connection loss during call to Disconnect() (including test)

Merge pull request #431 from fulder/master

Add Proxy to WebsocketOptions

Merge pull request #482 from ChIoT-Tech/master

Remove markdown code blocks from comments (as godoc does not handle this)

Update README.md

Clarify issue around messages arriving before subscribe can be called.

Merge pull request #462 from ChIoT-Tech/docs

Update godoc references to pkg.go.dev