Add a new endpoint to retrieve information from the wallabag instance

Useful for api client which required some information.
We might add more inside them in the future.

The endpoint /api/version should be avoided now as it contains not so much information rather the version.

src/Wallabag/ApiBundle/Controller/WallabagRestController.php

@@ -14,6 +14,8 @@ class WallabagRestController extends FOSRestController
      *
      * @ApiDoc()
      *
+     * @deprecated Should use info endpoint instead
+     *
      * @return JsonResponse
      */
     public function getVersionAction()
@@ -24,6 +26,24 @@ class WallabagRestController extends FOSRestController
         return (new JsonResponse())->setJson($json);
     }
 
+    /**
+     * Retrieve information about the wallabag instance.
+     *
+     * @ApiDoc()
+     *
+     * @return JsonResponse
+     */
+    public function getInfoAction()
+    {
+        $info = [
+            'appname' => 'wallabag',
+            'version' => $this->container->getParameter('wallabag_core.version'),
+            'allowed_registration' => $this->container->getParameter('wallabag_user.registration_enabled'),
+        ];
+
+        return (new JsonResponse())->setJson($this->get('jms_serializer')->serialize($info, 'json'));
+    }
+
     protected function validateAuthentication()
     {
         if (false === $this->get('security.authorization_checker')->isGranted('IS_AUTHENTICATED_FULLY')) {