[reSIProcate] DTLS things to think about

[Cullen Jennings]

make DTLS the transport for DTLS over UDP? What about DCCP? Assume TLS is
TLS over TCP?

use UdpTransport as base for adding stuff

need to add structure to keep track of multiple contexts

How do you tell which context to use on an incoming messages

how to clean up contexts ? LRU?

What do do if get incoming but have "closed" connection by dropping context
out of LRU?

How to explicitly "close" to delete a context