Erase Request from stream2req when stream is closed.

Added --verify-client option to spdyd.

Move timeout checking into the query parameter condition.  Copy last_modified date string for file responses.

Add a timeout to spdycat

Add a timeout parameter to spdycat and add a crazy parameter to spdyd to test it (or test other clients)

The spdylay_data contains full of implementation details and is not
used in public API. It should be hidden.
The spdylay_frame union now only contains the control frame.

Spdylay library itself does not depend on OpenSSL. The example programs
in examples directory do. Spdylay library should be built without
OpenSSL.

Made spdylay_session_get_pri_lowest() to get the lowest priority value
for the current session.

This change allows the application code to get the lowest priority value
without knowing the protocol version which the current session uses.