Merge branch '2.7' into 2.8

* 2.7:
  Remove usage of __CLASS__ outside of a class
  [HttpKernel] Fix variable conflicting name
  [Process] Fix double-fread() when reading unix pipes
  [Process] Fix AbstractPipes::write() for a situation seen on HHVM (at least)
  [Validator] Fix dockblock typehint in XmlFileLoader
  bumped Symfony version to 2.7.17
  updated VERSION for 2.7.16
  update CONTRIBUTORS for 2.7.16
  updated CHANGELOG for 2.7.16

Conflicts:
	src/Symfony/Component/HttpKernel/Kernel.php

Author: nicolas-grekas

Kernel.php

@@ -466,8 +466,8 @@ protected function initializeBundles()
                 $hierarchy[] = $name;
             }
 
-            foreach ($hierarchy as $bundle) {
-                $this->bundleMap[$bundle] = $bundleMap;
+            foreach ($hierarchy as $hierarchyBundle) {
+                $this->bundleMap[$hierarchyBundle] = $bundleMap;
                 array_pop($bundleMap);
             }
         }