Implemented Add Button

Added a button to add an URL when directly into Poche. If JS isn't
enabled, nothing happens.

inc/poche/Poche.class.php

@@ -558,4 +558,9 @@ class Poche
         }
         return $version;
     }
+
+    function convertURLToBase64($plainurl){
+        $convertedURL = base64_encode($plainurl);
+        $this->action('add', new Url($convertedURL))
+   }
 }