Add support for configurable CW clickthrough.

src/components/settings/settings.vue

@@ -34,6 +34,10 @@
           <input type="checkbox" id="hoverPreview" v-model="hoverPreviewLocal">
           <label for="hoverPreview">{{$t('settings.reply_link_preview')}}</label>
         </li>
+        <li>
+          <input type="checkbox" id="expandCW" v-model="expandCWLocal">
+          <label for="expandCW">{{$t('settings.expand_cw')}}</label>
+        </li>
       </ul>
     </div>
     <div class="setting-item">