Merge branch '2.8' into 3.0

* 2.8:
  add @event annotation for AuthenticationEvents
  bumped Symfony version to 2.8.6
  [PropertyInfo] PHPDoc correction
  add @event annotation for KernelEvents
  updated VERSION for 2.8.5
  updated CHANGELOG for 2.8.5
  bumped Symfony version to 2.7.13
  updated VERSION for 2.7.12
  update CONTRIBUTORS for 2.7.12
  updated CHANGELOG for 2.7.12
  bumped Symfony version to 2.3.41
  updated VERSION for 2.3.40
  update CONTRIBUTORS for 2.3.40
  updated CHANGELOG for 2.3.40
  Revert "minor #18257 [Routing] Don't needlessly execute strtr's as they are fairly expensive (arjenm)"
  Revert "fixed CS"
  fixed deprecation notices in tests
  [Security] Normalize "symfony/security-acl" dependency versions across all composer.json files
  [FrameworkBundle] Remove misleading comment
  bug #17460 [DI] fix ambiguous services schema

Author: fabpot

Loader/schema/dic/services/services-1.0.xsd

@@ -24,14 +24,28 @@
       ]]></xsd:documentation>
     </xsd:annotation>
     <xsd:sequence>
-      <xsd:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded" />
-      <xsd:element name="imports" type="imports" minOccurs="0" maxOccurs="1" />
-      <xsd:element name="parameters" type="parameters" minOccurs="0" maxOccurs="1" />
-      <xsd:element name="services" type="services" minOccurs="0" maxOccurs="1" />
-      <xsd:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded" />
+      <xsd:group ref="foreign" />
+      <xsd:sequence minOccurs="0">
+        <xsd:element name="imports" type="imports" />
+        <xsd:group ref="foreign" />
+      </xsd:sequence>
+      <xsd:sequence minOccurs="0">
+        <xsd:element name="parameters" type="parameters" />
+        <xsd:group ref="foreign" />
+      </xsd:sequence>
+      <xsd:sequence minOccurs="0">
+        <xsd:element name="services" type="services" />
+        <xsd:group ref="foreign" />
+      </xsd:sequence>
     </xsd:sequence>
   </xsd:complexType>
 
+  <xsd:group name="foreign">
+    <xsd:sequence>
+      <xsd:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded" />
+    </xsd:sequence>
+  </xsd:group>
+
   <xsd:complexType name="services">
     <xsd:annotation>
       <xsd:documentation><![CDATA[