bootstrap 4 update and bugfixes

app/plugins/blog/views/sidebar.html

@@ -1,8 +1,8 @@
-<div class="panel panel-info">
-    <div class="panel-heading">
-        <h3 class="panel-title">Recent Posts</h3>
+<div class="card panel-info">
+    <div class="card-header">
+        <h3 class="card-title">Recent Posts</h3>
     </div>
-    <div class="panel-body">
+    <div class="card-body">
         <ol class="list-unstyled">
             {LOOP}
                 <li><a href="{ROOT_URL}blog/post/{ID}">{title}</a></li>
@@ -12,7 +12,7 @@
             {/ALT}
         </ol>
     </div>
-    <div class="panel-footer">
+    <div class="card-footer">
         <a href="{ROOT_URL}blog">View All</a>
     </div>
 </div>