removed extraneous whitespaces
Fixed NativeSessionStorage:regenerate when does not exists
Merge branch '2.2' into 2.3

* 2.2:
  fixed typo
  bumped Symfony version to 2.2.5
  updated VERSION for 2.2.4
  update CONTRIBUTORS for 2.2.4
  updated CHANGELOG for 2.2.4
  Fixed NativeSessionStorage:regenerate when does not exists
  removed extraneous whitespaces

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