Hiera setup simplification

[kpaulisse]

Overview

This pull request changes the defaults for the Hiera configuration to match the Puppet control repo template and the default installation of Puppet Enterprise.

It also introduces a new option --hiera-path PATH to specify the relative path to hieradata. This passes through the relative directory to the munged hiera.yaml file. This is an alternative to --hiera-path-strip PATH which will reference the settings from the existing hiera.yaml file and subtract the specified path. Since most humans tend to find a positive declaration easier than a negative one, this should simplify the setup for many people.

Checklist

• Make sure that all of the tests pass, and fix any that don't. Just run rake in your checkout directory, or review the CI job triggered whenever you push to a pull request.
• Make sure that there is 100% test coverage by running rake coverage:spec or ignoring untestable sections of code with # :nocov comments. If you need help getting to 100% coverage please ask; however, don't just submit code with no tests.
• If you have added a new command line option, we would greatly appreciate a corresponding integration test that exercises it from start to finish. This is optional but recommended.