#4443 [HHQ-4302] Add support to monitor Postgres 8.4

[Hyperic Team]

http://jira.hyperic.com/browse/HHQ-4302
The latest version for postgres we support is 8.3. Postrgres 8.4 was GAed more then a year ago and according to Alexandre many vmware products already come packaged with postgres (not sure if 8.4) we should keep the plugin up-to-date.