This is a simple naming change PR, to fix the fact that "metadata" is a
single English word, and for too long we have not followed general
naming conventions for it. We are also not consistent about it, for
example, METADATA instead of META_DATA if we were trying to be
consistent with MetaData (although METADATA is correct when considered
in the context of "metadata"). This was a simple find and replace across
the code base, only taking a few minutes to fix this naming issue
forever.
This commit adds a check that any class in X-Pack that is a feature
aware custom also implements the appropriate mix-in interface in
X-Pack. These interfaces provide a default implementation of
FeatureAware#getRequiredFeature that returns that x-pack is the required
feature. By implementing this interface, this gives a consistent way for
X-Pack feature aware customs to return the appopriate required feature
and this check enforces that all such feature aware customs return the
appropriate required feature.
Jason Tedor
Tanguy Leroux