Fixed parsing of leading blank lines in folded scalars. Closes #7989.
Merge branch '2.1' into 2.2

* 2.1:
  Fixed XML syntax.
  Fixed parsing of leading blank lines in folded scalars. Closes #7989.
  Added a test case for Loader::import().
  Fixed Loader import
  [Console] Added dedicated testcase for HelperSet class
Merge branch '2.2'

* 2.2:
  fixed CS
  Fixed XML syntax.
  Fixed parsing of leading blank lines in folded scalars. Closes #7989.
  [Form] Fixed a method name.
  Added a test case for Loader::import().
  Fixed Loader import
  [Console] Added dedicated testcase for HelperSet class
  [Serializer] fixed CS (refs #7971)
  Fixed fatal error in normalize/denormalizeObject.
  Fixed 2 namespaces

Conflicts:
	src/Symfony/Component/HttpKernel/Debug/ErrorHandler.php
	src/Symfony/Component/HttpKernel/Tests/Fragment/InlineFragmentRendererTest.php