Update tor-spec.txt to reflect proposal 198 ("Restore semantics of TLS ClientHello")

I just merged #4744 (moved) into master, to implement the client side of Proposal 198. We should update tor-spec.txt to match.

changed milestone to %Tor: 0.2.3.x-final

added component::core tor/tor milestone::Tor: 0.2.3.x-final priority::medium resolution::fixed status::closed tor-client type::task labels

See branch "prop198_merge" in my public torspec repo.

Trac:
Status: new to needs_review

Merged.

Trac:
Status: needs_review to closed
Resolution: N/A to fixed

Trac:
Keywords: N/A deleted, tor-client added

Trac:
Component: Tor Client to Tor

closed

moved to tpo/core/tor#6144 (closed)