Current SPDY/3 spec does not clearly prohibit to send
delta_window_size which makes resulting window size more than initial
window size. For this reason, spdylay_submit_window_update() can send
delta_window_size in [1, (1 << 31)-1], inclusive, without bounded by
stream's recv_window_size. Of course, the application is now
responsible to keep the resulting window size <= (1 << 31)-1.

spdylay_submit_window_update() now returns
SPDYLAY_ERR_INVALID_ARGUMENT if delta_window_size is 0 or negative.

Print, for each stream, time delta from SSL/TLS handshake and each
SYN_STREAM. The time deltas are measured after SYN_REPLY received and
all data received.
For example, the following output:

  SYN_REPLY: X(Y)

means SYN_REPLY was received X ms after SSL/TLS handshake and Y ms
after the corresponding SYN_STREAM was sent.

If this option is used, spdycat also downloads assets such as
stylesheets, images and script files linked from the downloaded
resource. They are queued in the same SPDY session.

This is because compiler may warn that name `index` shadows global
declaration if the application code uses the prototype argument names
as is.

Updated program output to the latest version. Mentioned spdycli.

SPDYLAY_ERR_TEMPORAL_CALLBACK_FAILURE to signal stream error.

when WINDOW_UPDATE is received.

INITIAL_WINDOW_SIZE is received and the window size becomes positive.