Bug 1127410 - WARN [ResourceDiscoveryComponent.invoker.daemon-10] (org.rhq.plugins.postgres.PostgresDiscoveryComponent)- PostgreSQL data directory (/var/lib/pgsql/data) does not exist or is not readable

Log at debug level in discovery code (which is called often)
Log problems with the config file only once when the resource component
is started

Also, some code cleanup