Add "clone" as an option when creating a new version of an app/service/plan

This feature has been on the roadmap, but apparently I didn't have a JIRA for it. We should add a checkbox (default to checked) when creating a new version of an app or service or plan. The checkbox should be labeled something like "Clone existing settings". When this is checked we'll create a new version of the entity but also copy over all its meta-data, policies, etc to the new version.