Added PostgreSQL 9.3 to Autoparts

When dealing with both versions, the last package which is installed is what will take precedence. I've tested both versions and works.

* New package pulls in install methods from PostgreSQL package.
* Modified package to remove /home/action/.parts/var/postgresql/postgresql.conf upon purge.

Before merging we will need to update support docs and also create binaries. I can do this once this once given the "okay" to merge.