obsolete: introduce an `_enabled` switch to disable the feature by default...
obsolete: introduce an `_enabled` switch to disable the feature by default
Obsolete markers wide-usage and propagation should be avoided by default until
the obsolete feature is more mature.
This changeset introduce the `_enable` variable and prevent the creation of
obsolete marker if the feature is set to `False` (the default).
More limitation comes in followup changesets.