OpenBSD support

Patch below adds support for OpenBSD. 

Due to differences, the puppet_service_name and embedded_subname had to be made dependent on osfamily.

Note: This only adds support for OpenBSD 5.6-current, which means, needs at least puppetdb-2.1.0p1 package 
installed on OpenBSD. Prior versions had a single puppetdb/conf.d/puppetdb.conf file, instead of the
multiple configuration files. 

Note: To make the change below work, my pull request for OpenBSD support to puppetlabs/postgresql needs to be added to that module.