First official release.
Features:
* Standard Manifest file definition created
* `ManifestBase` class that can be extended to implement manifest processing classes where the class name correlates to the manifest kind
* `ManifestManager` class to orchestrate the processing of multiple processing classes and manifest files
* `VariableCache` shared across all class implementations to share data
* Selective processing skip flag in manifest
* Manifest dependency support
* Command line usage or docker option to apply/delete manifests