coaps (CoAP over DTLS) support as described in RFC 7252 section-9.1

[dgtlrift]

Is your feature request related to a problem? Please describe.
coap post coaps://192.168.0.4/message

Describe the solution you'd like
Initiate a DTLS exchange and transport CoAP over that secure DTLS link

Describe alternatives you've considered
Tunnel CoAP over TCP-TLS link - may be intractable for mesh devices

Additional context
Add any other context or screenshots about the feature request here.
https://tools.ietf.org/html/rfc7252#section-9.1