Keep 308-399 HTTP response codes when header('Location:') is called.

Fixes bug #67428 (header('Location: foo') will override a 308-399 response
code).
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Keep 308-399 HTTP response codes when header('Location:') is called.
Merge branch 'PHP-5.5' into PHP-5.6

* PHP-5.5:
  Keep 308-399 HTTP response codes when header('Location:') is called.