The comments in Outbound::recognize had become somewhat stale as the
logic changed. Furthermore, this implementation may be easier to
understand if broken into smaller pieces.

This change reorganizes the Outbound:recognize method into helper
methods--`destination`, `host_port`, and `normalize`--each with
accompanying docstrings that more accurately reflect the current
implementation.

This also has the side-effect benefit of eliminating a string clone on
every request.