ID-32 support; a couple of bug fixes

• [FEATURE] QUIC and HTTP/3 Internet Draft 31 support. Drop ID-30 and ID-31 support.
• [BUGFIX] Divide-by-zero in newly enabled conn stats code when no packets were sent.
• [BUGFIX] Memory leak in gQUIC client when server hello cannot be parsed.
• [BUGFIX] Server Initial packet size calculation.
• Log user-agent and CONN_CLOSE reason when peer reports error.
• Example programs: Specify ALPN for echo and md5 clients and servers (issue #184).
• Example programs: Don't add "QUIC_" prefix to lines in keylog file (issue #185).
• http_server: Fix fd leak in preadv mode; fix preadv() usage when reading from disk.

Revert 2.12.11

Release 2.12.12

Undo change in 2.12.11

Fix packetization threshold

• [BUGFIX] Update packetization threshold when writing to stream after packet size is reduced following an RTO.

QPACK experiments, log connection stats

• Add QPACK stats collection and experimentation mode, see the new es_qpack_experiment setting.
• Log busy connection stats every second using the new "conn-stats" log module.
• Log about skipping only once.
• Update HTTP/3 greased frame type formula.
• Use ls-qpack v2.2.1.

Client 0-RTT support; bug fixes

• [FEATURE] IETF Client 0-RTT support.
• [BUGFIX] Do not schedule MTU probe on first tick.
• [BUGFIX] Parsing DATAGRAM frame.
• [BUGFIX] If push promise fails, do not invoke hset destructor.
• [BUGFIX] Client: When connections are IDed by port number, check DCID. Fixes issue #176.
• [BUGFIX] Regression introduced in 2.22.0: use correct number of PNSs for IETF mini conn during promotion.
• Revert the 2.22.1 lsquic_is_valid_hs_packet change. All that was necessary is a change to the way we call it in lsquic_engine. No change to the function itself is required.

Fix function that checks validity of handshake packets

Release 2.12.11

- [BUGFIX] Function that checks validity of handshake packets

Extensible HTTP Priorities and more; bug fixes

• [FEATURE] Extensible HTTP Priorities (HTTP/3 only).
• [FEATURE] Add conn context to packet-out memory interface (PR #175).
• [BUGFIX] gQUIC proof generation: allocate buffer big enough for signature (issue #173).
• [BUGFIX] Make library thread-safe: drop use of global variables (issue #133, issue #167).
• [BUGFIX] Deactivate only recent HQ frame, not any HQ frame.
• [BUGFIX] gQUIC server: associate compressed cert with SSL_CTX, instead of keeping them in a separate hash, potentially leading to mismatches.
• [BUGFIX] Stream data discard infinite loop: break on FIN.
• cmake: add install target via -DCMAKE_INSTALL_PREFIX (PR #171).
• Support randomized packet number to begin a connection.
• Mini and full IETF connection size optimization.
• http_client: specify HTTP priorities based on stream conditions.

Fix HQ frame deactivation

Release 2.12.10

- [BUGFIX] Deactivate only *recent* HQ frame, not any HQ frame.

Features: ID-31, connection ID steering, shared library

• [FEATURE] QUIC and HTTP/3 Internet Draft 31 support.
• [API] Let user generate Souce Connection IDs.
• [FEATURE] Allow building lsquic as shared library.
• [OPTIMIZATION] Receive history: use a single contiguous memory block for everything.
• Deprecate QUIC versions ID-27 and ID-30.

Fix memory leaks

• [BUGFIX] Memory leak: free pushed promise when refcnt is zero.
• [BUGFIX] Memory leak in IETF full conn dtor: cleanup closed IDs sets.