Enhancement : Content negotiation reply interface helper
Enhancement : Content negotiation reply interface helper

Added a helper function to get an appropriate reply interface from the value contained in an `Accept` header.
Defaults to the `application/json` interface.

Signed-off-by: davemackintosh <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@davemackintosh.co.uk>

newworldcode/multicolour-server-hapi,Multicolour/multicolour-server-hapi