Add upstream plugins

Signed-off-by: Adrian Nöthlich <git@promasu.tech>

wp-content/plugins/all-in-one-event-calendar/public/admin/base_page.php

@@ -0,0 +1,19 @@
+<div class="wrap">
+
+    <h2><?php echo $page->title; ?></h2>
+
+    <div id="poststuff">
+
+        <form method="post" action="">
+            <?php wp_nonce_field( 'update', 'simple_page_nonce' ); ?>
+
+            <div class="metabox-holder">
+                <div class="post-box-container left-side timely">
+                    <?php $template_adapter->display_meta_box( $page->meta_box_id, 'left-side', null ); ?>
+                </div>
+            </div>
+        </form>
+
+    </div><!-- #poststuff -->
+
+</div><!-- .wrap -->