h2 tests and deproxy h2 update

[RomanBelozerov]

Now deproxy h2 client can:

• send settings frame;
• update default settings before create connection;
• accept settings frame with ack flag;
• wait settings frame with ack flag;
• saves error codes;
• send bytes;

handle_read method for deproxy h2 client - now method variable is created when client receives ResponseReceived event. This fixes error of receiving frames other than headers.

Added tests for issue #88:

Verification of correct frames exchange during establishing of h2 connection: get correct SETTINGS frame (with SETTINGS_INITIAL_WINDOW_SIZE parameter), correct WINDOW_UPDATE frame and correct SETTINGS ACK frame.

HPACK entries eviction: we must correctly process the maximum dynamic table and evict old entries - the test must define the table limit and send too many different headers

Use small SETTINGS_MAX_FRAME_SIZE on a client and test that HTTP response headers and body are normally fragmented

Stream IDs: (1) check that even IDs and ID > 0x7fffffff aren't accepted and (2) you cannot reuse old ID (see Victim 1–HTTP/2 Stream Multiplexing (CVE-2016-0150))

For all cases from issue #344

For issue #1394:

Doesn't send more than allowed by per-stream flow control

Added some tests for RFC 7541 and 9113.