Pg data support

This pull request implements support for changing PGDATA from default values. It also implements ability to change PGDATA if ever needed on a running server by leveraging same method as port changing in config_entry.pp.

Tested on CentOS 6.x against PostgreSQL 9.3 - additional patch will follow for this as PostgreSQL version 9.3 and higher implement different values in /etc/sysconfig/pgsql and init script breaks.