...

Add configuration unstable.feature.version.enable to allow for non production ready features to be used (for testing). Using features that are not production ready has risks and may result in the cluster with this feature being unable to upgrade to a future release or even a more recent build from trunk.
unstable.metadata.versions.enable will be deprecated.

Proposed Changes

No argument behavior on the storage and upgrade tools is to set all the features to the latest stable version.

For both tools:

...