DP-20 #resolve #comment Optimise local message passing

We skip the transport layer altogether for local send and write directly
to the local NC control channel. Local sends do serialise the message
(to ensure HNF) but we pass the unencoded data along with a fingerprint.
Subsequent reads utilise unsafeCoerce if fingerprint comparison on the
types succeeds.
Merge branch 'local-send' into development