This is good, though I'd like to point to the service provider for a second:

https://github.com/puppetlabs/puppet/commit/a25e2cc2ef72d2549c84a91d75c587ecbfabfe4f#diff-602361155f8f9fbe8f754138ed6f22b9

As of Puppet 3.6.0 the service provider in OpenBSD has the 'flags' property.  This should enable the functionality that we need here.  It also handles the pkg_scripts line, which I notice is missing here.

I don't know the version of Puppet included in the recent 5.5, but I think 3.6.0 Puppet was released later.  It seems reasonable to merge this now considering the support for this feature is not available in OpenBSD, but just noting it here so that we can switch the implementation later.  Help me remember? :)