Bug 1150736 - Add timestamp to postgresql logs

This will prefix postgresql logs with timestamp:

```
 ~/sandbox/rubyapp/rubyapp2 → rhc tail
==> app-root/logs/postgresql.log <==
2014-10-09 16:17:08 GMT LOG:  could not bind socket for statistics collector: Permission denied
2014-10-09 16:17:08 GMT LOG:  disabling statistics collector for lack of working socket
2014-10-09 16:17:08 GMT WARNING:  autovacuum not started because of misconfiguration

```