SPDY client example

Demonstrates the usage of SPDY from a client perspective. One can also
use a SPDY-enabled browser as a client, but it’s easier to understand
the internals of the protocol from a client point-of-view if you have
some code you can debug.
Reorganize the SPDY example

- Move the server example to spdy.server
- Move the client example to spdy.client
- Fix inspection warnings