tor-spec: Change OR/OP to relay/client in some remaining places.
In combination with !283 (merged) and !286 (merged) this should take care of all of the usages of "OR" and "OP" in the "Tor Protocol Specification" section of the spec.
In combination with !283 (merged) and !286 (merged) this should take care of all of the usages of "OR" and "OP" in the "Tor Protocol Specification" section of the spec.