add CSS for RoomAvatarEvent and always make AccessibleButtons have a cursor pointer

src/skins/vector/css/_components.scss

@@ -33,6 +33,7 @@
 @import "./matrix-react-sdk/views/messages/_MImageBody.scss";
 @import "./matrix-react-sdk/views/messages/_MNoticeBody.scss";
 @import "./matrix-react-sdk/views/messages/_MTextBody.scss";
+@import "./matrix-react-sdk/views/messages/_RoomAvatarEvent.scss";
 @import "./matrix-react-sdk/views/messages/_TextualEvent.scss";
 @import "./matrix-react-sdk/views/messages/_UnknownBody.scss";
 @import "./matrix-react-sdk/views/rooms/_Autocomplete.scss";

src/skins/vector/css/matrix-react-sdk/views/elements/_AccessibleButton.scss

@@ -19,3 +19,6 @@ limitations under the License.
     filter: brightness($focus-brightness);
 }
 
+.mx_AccessibleButton {
+    cursor: pointer;
+}

src/skins/vector/css/matrix-react-sdk/views/messages/_RoomAvatarEvent.scss

@@ -0,0 +1,24 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_RoomAvatarEvent {
+    opacity: 0.5;
+    overflow-y: hidden;
+}
+
+.mx_RoomAvatarEvent_avatar {
+    display: inline;
+}