Show an indicator when there are any pins in the room

Signed-off-by: Travis Ralston <travpc@gmail.com>

src/utils/PinningUtils.js

@@ -0,0 +1,30 @@
+/*
+Copyright 2017 Travis Ralston
+
+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.
+*/
+
+export default class PinningUtils {
+    /**
+     * Determines if the given event may be pinned.
+     * @param {MatrixEvent} event The event to check.
+     * @return {boolean} True if the event may be pinned, false otherwise.
+     */
+    static isPinnable(event) {
+        if (!event) return false;
+        if (event.getType() !== "m.room.message") return false;
+        if (event.isRedacted()) return false;
+
+        return true;
+    }
+}