$useHeadElement = false; is no longer supported and will not cause old keys
like "headlinks", "skinnameclass", etc. to be defined.
* The deprecated 'SpecialVersionExtensionTypes' hook was removed.
+* (bug 63891) Add 'X-Robots-Tag: noindex' header in action=render pages.
==== Renamed classes ====
* CLDRPluralRuleConverter_Expression to CLDRPluralRuleConverterExpression