Added new defaults for cipher suites and protocols.

Added new defaults for cipher suites and protocols.

https://github.com/square/okhttp/issues/330
https://github.com/square/okhttp/issues/919
I think we probably want a quick API to revert to the backwards-compatible protocol schemes. Especially in RouteSelector where the set of TLS versions is actually exercised. But we can probably do this in a follow-up change.