Merge branch '2.8' into 3.0

* 2.8:
  [2.7] Fix tests
  pass triggerDeprecationError arg to parent class
  remove default null value for asset version
  remove duplicated value
  [Ldap] Remove unused private property
  Update UPGRADE-3.0 with correct Voter details
  Change few occurences of a public setUp() method to protected
  [DependencyInjection] simplify the BC layer
  Change couple of occurences of a public setUp() method to protected

Author: fabpot

LdapClient.php

@@ -30,7 +30,6 @@ class LdapClient implements LdapClientInterface
     private $useStartTls;
     private $optReferrals;
     private $connection;
-    private $charmaps;
 
     /**
      * Constructor.