get rid of routerstatus->version_supports_optimistic_data

Clients are now willing to send optimistic circuit data (before they
receive a 'connected' cell) to relays of any version. We used to
only do it for relays running 0.2.3.1-alpha or later, but now all
relays are new enough.

Resolves ticket 13153.
Use optimistic data even if we don't know exitnode->rs

I think we should know the routerstatus for our exit relay, since
we built a circuit to it. So I think this is just a code simplication.
clients use optimistic data when reaching hidden services

Allow clients to use optimistic data when connecting to a hidden service,
which should cut out the initial round-trip for client-side programs
including Tor Browser.

(Now that Tor 0.2.2.x is obsolete, all hidden services should support
server-side optimistic data.)

See proposal 181 for details. Implements ticket 13211.
Merge remote-tracking branch 'arma/feature13153'
Merge remote-tracking branch 'arma/feature13211'
Remove config options that have been obsolete since 0.2.3
changes file for 12884