Adding PostgreSQL 9.3 support for Ubuntu 14.04

- Added conditional support for PostgreSQL 9.3.
- Added conf_dir and create_cluster variables to denote actions based on
  OS / release.
Fixing issues with Centos (initdb, and service name).
Removing the static 9.3 from init.sls, moving it to a variable.
Added the ability to add custom configuration to the postgresql.conf configuration file.
Merge pull request #19 from berry-langerak/bugfix/adding-postgresql-9.3-support

Adding PostgreSQL 9.3 support for Ubuntu 14.04
Fixing merge conflict.
Re-adding variables that I removed by accident.:
Merge pull request #20 from berry-langerak/feature/adding-config-to-postgresql-conf

Added the ability to add custom configuration to postgresql.conf.
fix host ACL in pillar.example
Merge pull request #22 from blbradley/example-pillar-acl-fix

Host ACL in pillar.example has host and user backward