remove docgen remnants from repo, update CHANGELOG

utils/apidoc/lib/metadata.dart

Index: utils/apidoc/lib/metadata.dart
diff --git a/utils/apidoc/lib/metadata.dart b/utils/apidoc/lib/metadata.dart
deleted file mode 100644
index c56b0b6a658c6b2a127943761a7d252af2b6d9f7..0000000000000000000000000000000000000000
--- a/utils/apidoc/lib/metadata.dart
+++ /dev/null
@@ -1,15 +0,0 @@
-library metadata;
-
-import '../../../pkg/compiler/lib/src/mirrors/source_mirrors.dart';
-import '../../../pkg/compiler/lib/src/mirrors/mirrors_util.dart';
-
-/// Returns the metadata for the given string or null if not found.
-InstanceMirror findMetadata(List<InstanceMirror> metadataList, String find) {
-  return metadataList.firstWhere(
-      (metadata) {
-        if (metadata is TypeInstanceMirror) {
-          return nameOf(metadata.representedType) == find;
-        }
-        return nameOf(metadata.type) == find;
-      }, orElse: () => null);
-}