Brian Schwind

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Subscription_Options

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901116

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901113

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901050

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Flow_Control

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901066

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901112

Spec: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901250

Make matching_subscribers function return an iterator

1

Assuming we can do it in an efficient way, it would be nicer to have the `matching_subscribers` function return an iterator instead of accepting an element callback. Relevant code: https://github.com/bschwind/mqtt-broker/blob/1533c5c355d8d77cde194f2550533e3b6f3d22e2/mqtt-v5-broker/src/tree.rs#L202-L241

Add TLS Support

1

Ideally with integration for LetsEncrypt to have automatic, self-renewing certificates.