clarified deprecation messages

Twig/Extension/SonataAdminExtension.php

@@ -321,7 +321,8 @@ EOT;
 
             if ($method) {
                 @trigger_error(
-                    'Option "associated_tostring" is deprecated since version 2.3. Use "associated_property" instead.',
+                    'Option "associated_tostring" is deprecated since version 2.3 and will be removed in 4.0. '
+                    .'Use "associated_property" instead.',
                     E_USER_DEPRECATED
                 );
             } else {

Util/AdminObjectAclData.php

@@ -176,7 +176,11 @@ class AdminObjectAclData
      */
     public function setForm(Form $form)
     {
-        @trigger_error('setForm() is deprecated since version 3.0. Use setAclUsersForm() instead.', E_USER_DEPRECATED);
+        @trigger_error(
+            'setForm() is deprecated since version 3.0 and will be removed in 4.0. '
+            .'Use setAclUsersForm() instead.',
+            E_USER_DEPRECATED
+        );
 
         return $this->setAclUsersForm($form);
     }
@@ -190,7 +194,11 @@ class AdminObjectAclData
      */
     public function getForm()
     {
-        @trigger_error('getForm() is deprecated since version 3.0. Use getAclUsersForm() instead.', E_USER_DEPRECATED);
+        @trigger_error(
+            'getForm() is deprecated since version 3.0 and will be removed in 4.0. '
+            .'Use getAclUsersForm() instead.',
+            E_USER_DEPRECATED
+        );
 
         return $this->getAclUsersForm();
     }

Util/AdminObjectAclManipulator.php

@@ -72,7 +72,11 @@ class AdminObjectAclManipulator
      */
     public function createForm(AdminObjectAclData $data)
     {
-        @trigger_error('createForm() is deprecated since version 3.0. Use createAclUsersForm() instead.', E_USER_DEPRECATED);
+        @trigger_error(
+            'createForm() is deprecated since version 3.0 and will be removed in 4.0. '
+            .'Use createAclUsersForm() instead.',
+            E_USER_DEPRECATED
+        );
 
         return $this->createAclUsersForm($data);
     }
@@ -146,7 +150,11 @@ class AdminObjectAclManipulator
      */
     public function updateAcl(AdminObjectAclData $data)
     {
-        @trigger_error('updateAcl() is deprecated since version 3.0. Use updateAclUsers() instead.', E_USER_DEPRECATED);
+        @trigger_error(
+            'updateAcl() is deprecated since version 3.0 and will be removed in 4.0.'
+            .'Use updateAclUsers() instead.',
+            E_USER_DEPRECATED
+        );
 
         $this->updateAclUsers($data);
     }