The deprecation process is unclear in that it does not specify the goals of
hiding (rather than removing) obsolete resource types. This has led to
resources being hidden without removing their implementation, leaving
existing stacks potentially inoperable.
State clearly the purpose of hidden resource types, and options available
to help users migrate.
Change-Id: I7362c094122066f98a5c95d4c5da16cb5a5c1108