pgpool: Feature: Restrict watchdog and heartbeat receiver to listen onl

Feature: Restrict watchdog and heartbeat receiver to listen only on configured addresses.

Previously, both the watchdog and heartbeat receiver processes listen on all interfaces.
For security reasons, they now listen only on the addresses
specified by "hostname" and "heartbeat_hostname".

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=94b62a93c149bdaa7c546e387e479c287d3e10f9

Modified Files
--------------
src/config/pool_config_variables.c | 67 ++++++++++++++++++++++++++------------
src/include/pool_config.h | 5 +--
src/watchdog/watchdog.c | 8 ++---
src/watchdog/wd_heartbeat.c | 8 ++---
src/watchdog/wd_lifecheck.c | 33 +++++++++++++------
5 files changed, 80 insertions(+), 41 deletions(-)