Fix outbound flow control count

We wrongly added the whole payload length even if we sent part of it.
src: Remove unused function/member
tests: Fix main test fail with address-sanitizer
tests: Fix memory leak
tests: Remove unused variable
shrpx: Check DATA_FLAG_FIN on on_data_recv_callback
spdycat, spdyd: Add --color option to force colored log output
shrpx: Add --verify-client option

This option requires client certificate and successful verification.
Use --cacert option to add CA certificates as necessary.
shrpx: Add --verify-client-cacert option

Using --cacert to load certificate for client certificate
authentication is problematic since, --cacert is also used for client
mode.  This commit adds --verify-client-cacert option which specify
the CA certficate file used only for client certificate validation.
This change also removes the default certficate load function for
client certificate validation.
src/http-parser: Update to HEAD
src/http-parser: Apply tunnel patch
src/http-parser: Allow custom HTTP-version string (e.g., ICY)

We need HTTP major and minor version later, so we assume it is
HTTP/1.0 equivalent if custom HTTP-version string is used.
Add SPDY/3.1 support

The added feature is connection-level flow control.  The
FLOW_CONTROL_ERROR status code for GOAWAY frame is not specified in
the SPDY/3.1 spec, so we use PROTOCOL_ERROR instead in this commit.

The tools in src directory supports SPDY in clear, but the option to
specify SPDY protocol lacks SPDY/3.1 support.
Remove false comment
src: Support spdy/3.1 in command-line option
Bump up version number to 1.2.0-DEV
Use subdir-objects automake option
Code cleanup
shrpx: Use initial window size from config directly
Update doc