Unify null comparisons
Merge branch '2.3' into 2.4

* 2.3:
  Update validators.eu.xlf
  fixed CS
  remove unused imports
  Unify null comparisons
  [EventDispatcher] don't count empty listeners
  [Process] Fix unit tests in sigchild environment
  [Process] fix signal handling in wait()
  [BrowserKit] refactor code and fix unquoted regex
  Fixed server HTTP_HOST port uri conversion
  Bring code into standard
  [Process] Add test to verify fix for issue #11421
  [Process] Fixes issue #11421
  [DependencyInjection] Pass a Scope instance instead of a scope name.

Conflicts:
	src/Symfony/Component/EventDispatcher/Tests/EventDispatcherTest.php
Merge branch '2.4' into 2.5

* 2.4:
  Update validators.eu.xlf
  fixed CS
  remove unused imports
  [Routing] simplify the XML schema file
  Unify null comparisons
  [EventDispatcher] don't count empty listeners
  [Process] Fix unit tests in sigchild environment
  [Process] fix signal handling in wait()
  [BrowserKit] refactor code and fix unquoted regex
  Fixed server HTTP_HOST port uri conversion
  [MonologBridge] fixed Console handler priorities
  Bring code into standard
  [Process] Add test to verify fix for issue #11421
  [Process] Fixes issue #11421
  [DependencyInjection] Pass a Scope instance instead of a scope name.

Conflicts:
	src/Symfony/Bundle/FrameworkBundle/Test/WebTestCase.php
	src/Symfony/Component/DependencyInjection/Tests/Dumper/GraphvizDumperTest.php
	src/Symfony/Component/PropertyAccess/Tests/PropertyAccessorCollectionTest.php