optimized circular reference checker
Merge branch '2.2' into 2.3

* 2.2:
  [Security] fixed some phpdoc
  Fixed PHPDoc Blocks
  optimized circular reference checker
  [HttpKernel] changed fragment URLs to be relative by default (closes #8458)
Merge branch '2.3'

* 2.3:
  [Security] fixed some phpdoc
  Fixed PHPDoc Blocks
  optimized circular reference checker
  fixed misleading doc block
  [HttpKernel] changed fragment URLs to be relative by default (closes #8458)

Conflicts:
	src/Symfony/Component/HttpKernel/Fragment/RoutableFragmentRenderer.php
	src/Symfony/Component/HttpKernel/Tests/Fragment/RoutableFragmentRendererTest.php