Add discussion list refresh button

Closes flarum/core#139. Haven’t done pull to refresh yet though, but
that can come later.

framework/core/js/forum/src/components/index-page.js

@@ -163,6 +163,15 @@ export default class IndexPage extends Component {
       })
     );
 
+    items.add('refresh',
+      ActionButton.component({
+        title: 'Refresh',
+        icon: 'refresh',
+        className: 'btn btn-default btn-icon',
+        onclick: () => app.cache.discussionList.refresh()
+      })
+    );
+
     return items;
   }
 

framework/core/less/forum/index.less

@@ -16,17 +16,27 @@
 .index-toolbar {
   margin-bottom: 15px;
 }
-.index-toolbar-view {
-  &:extend(.list-inline);
-
+.index-toolbar-view, .index-toolbar-action {
   display: inline-block;
   margin: 0;
+  list-style: none;
+  padding: 0;
+
+  & > li {
+    display: inline-block;
+  }
+}
+.index-toolbar-view {
+  & > li {
+    margin-right: 5px;
+  }
 }
 .index-toolbar-action {
-  &:extend(.list-inline);
-
   float: right;
-  margin: 0;
+
+  & > li {
+    margin-left: 5px;
+  }
 }
 
 @media @phone, @tablet {