A.21. Release 4.1.5

Doc: update "Aurora Configuration Example". (Bo Peng)

Doc: mention that GSSAPI is not supported. (Tatsuo Ishii)

Pgpool-II doesn't support GSSAPI. Allow Pgpool-II to deal with this issue and expects that the frontend falls back to other connections instead of responding with an error. (Tatsuo Ishii)

Patch is created by me, reviewed and tested by Umar Hayat.

Doc: update "Pgpool-II + Watchdog Setup Example". (Bo Peng)

Fix query rewrite syntax error of "INSERT ... ON CONFLICT" in native replication mode. (bug 654) (Bo Peng)

Fix connection counter was not counted down when query is canceled. (bug 656) (Tatsuo Ishii)

Doc: fix usable versions of PostgreSQL to be 7.4 or later. (Tatsuo Ishii)