Pe compatibility (2 of 5)

Resolve #148 before considering.

This is the second of several PRs refactoring this module to support management of MCollective in PE deployments.

This PR parameterizes the configuration directory for MCollective, the server package name, and the ssl_client_certs_dir. These are all things that differ between PE MCollective and the opensource MCollective packaging, and so must be parameterized if the module is to support managing both.