Add a key to the configuration with a version schema to differentiate versions.

[jharmison-redhat]

This will support parsing some of the configuration in the shim to identify if the schema needs to be migrated between incompatible versions.

It should be done in a way that identifies breaking changes as well as non-breaking changes. Introduction of an optional parameter, or extension of an Enum to support more values, should not break backwards compatibility. Restructuring of a section or removal of an Enum value should break backwards compatibility.