Release 2.19.8

- [FEATURE] Update the timestamp extension to latest version.
- [FEATURE] Cope with appearance of ECN blackholes.
- [OPTIMIZATION] return packno offset and size when header is generated.
- [BUGFIX] ignore old ACK frames in mini conns.
- [BUGFIX] Mark initial server path as initialized.
- [BUGFIX] Do not merge ACK if ECN counts do not match.
- Turn incoming packet number history in mini conn back on.
- Record mini conn event history again when compiled in debug mode.
- IETF mini conn: log when ACK is queued.
- Clean up and refactor code in several places.

tests/test_reg_pkt_headergen.c

@@ -220,7 +220,7 @@ run_test (int i)
 
     unsigned char out[GQUIC_MAX_PUBHDR_SZ];
     int len = test->pf->pf_gen_reg_pkt_header(&lconn, &packet_out, out,
-                                                                sizeof(out));
+                                                    sizeof(out), NULL, NULL);
 
     assert(("Packet length is correct", len == test->len));