Merge branch '2.3' into 2.6

* 2.3:
  [2.3][Debug] Fix fatal-errors handling on HHVM
  Standardize the name of the exception variables
  [2.3] Static Code Analysis for Components
  Remove duplicated paths

Conflicts:
	src/Symfony/Component/Debug/ErrorHandler.php
	src/Symfony/Component/HttpFoundation/Session/Storage/MockArraySessionStorage.php
	src/Symfony/Component/Security/Acl/Dbal/AclProvider.php
	src/Symfony/Component/Security/Core/Authentication/Provider/UserAuthenticationProvider.php

Author: nicolas-grekas

Compiler/ResolveInvalidReferencesPass.php

@@ -47,7 +47,7 @@ public function process(ContainerBuilder $container)
             foreach ($definition->getMethodCalls() as $call) {
                 try {
                     $calls[] = array($call[0], $this->processArguments($call[1], true));
-                } catch (RuntimeException $ignore) {
+                } catch (RuntimeException $e) {
                     // this call is simply removed
                 }
             }
@@ -58,7 +58,7 @@ public function process(ContainerBuilder $container)
                 try {
                     $value = $this->processArguments(array($value), true);
                     $properties[$name] = reset($value);
-                } catch (RuntimeException $ignore) {
+                } catch (RuntimeException $e) {
                     // ignore property
                 }
             }

Dumper/GraphvizDumper.php

@@ -278,7 +278,7 @@ private function addOptions($options)
      */
     private function dotize($id)
     {
-        return strtolower(preg_replace('/[^\w]/i', '_', $id));
+        return strtolower(preg_replace('/\W/i', '_', $id));
     }
 
     /**