#106 pg_hba.conf configuration in pgxc_ctl

[Koichi Suzuki]

Current pgxc_ctl takes care of pg_hba.conf entries only for XC owner and streaming replication. In real cases, we need the following feature:

1. Define initial pg_hba.conf general entries,
2. Add pg_hba.conf entries,
3. Remove pg_hba.conf entries

3 may not be simple. Instead, we may allow to reset all the pg_hba.conf entries from the configuration file.

In each cases, we should consider coordinator CIDs.