[perl-YAML-LibYAML/f17] Clean up and add patch for CVE-2012-1152 (CPAN RT#46507)

[Paul Howarth]

Summary of changes:

  2d5a824... Clean up and add patch for CVE-2012-1152 (CPAN RT#46507) (*)

(*) This commit already existed in another branch; no separate mail sent