Added PostgreSQL 9.3 to Autoparts

Please double check and let me know if this method is optimal for offering both pg9.2 and 9.3. When dealing with both versions, the last package which is installed is what will take precedence. I've tested both versions and works.

* Renamed postgresql package to postgresql9.2
* 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.