[pgpool-committers: 4993] pgpool: Add new log_client_messages directive.

[Tatsuo Ishii]

Add new log_client_messages directive.

This allows to log messages from frontend.

Note that the regression test for this (019.log_client_messages)
requires pgproto command.  We will eventually import pgproto in the
future but for now we just check the existence of pgproto in
019.log_client_messages/test.sh. If pgproto does not exist in the
command search pass, just skip the test with "ok" status.

Patch contributed by Takuma Hoshiai.

Branches
--------
SCRAM_AUTH
master

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=54503f4c87f1853ec1e71e65331adddc05531312

Modified Files
--------------
doc.ja/src/sgml/connection-pooling.sgml            |  28 ++++
doc/src/sgml/connection-pooling.sgml               |  18 +++
src/config/pool_config_variables.c                 |  10 ++
src/include/pool_config.h                          |   1 +
src/protocol/child.c                               |   4 +
src/protocol/pool_proto_modules.c                  |  67 +++++++-
src/sample/pgpool.conf.sample                      |   2 +
src/sample/pgpool.conf.sample-logical              |   2 +
src/sample/pgpool.conf.sample-master-slave         |   2 +
src/sample/pgpool.conf.sample-replication          |   2 +
src/sample/pgpool.conf.sample-stream               |   2 +
.../tests/019.log_client_messages/test.sh          | 169 +++++++++++++++++++++
src/utils/pool_process_reporting.c                 |   5 +
13 files changed, 311 insertions(+), 1 deletion(-)