Cache SPDY responses even if the body isn't fully consumed.

https://github.com/square/okhttp/issues/450
fix #447: Fix JettyNpnProvider.invoke() to pick the right protocol
fix #447: Fix JettyNpnProvider.invoke() to pick the right protocol
Merge pull request #454 from square/jwilson_0118_spdy_caches

Cache SPDY responses even if the body isn't fully consumed.
Merge pull request #455 from adriancole/client-npn

Fix JettyNpnProvider.invoke() to pick the right protocol