ruby security and bug fix update

[1.8.5-27]

• unintentional file creation caused by inserting an illegal NUL character
  • ruby-1.8.6-CVE-2012-4522-io.c-pipe_open-command-name-should-not-contain-null-.patch
  • Related: rhbz#867750

[1.8.5-26]

• escaping vulnerability about Exception#to_s / NameError#to_s

• ruby-1.8.7-p371-CVE-2012-4481.patch

• Resolves: rhbz#867750
• unintentional file creation caused by inserting an illegal NUL character
  • ruby-1.8.6-CVE-2012-4522-io.c-rb_open_file-should-check-NUL-in-path.patch
  • Resolves: rhbz#867750

[1.8.5-25]

• Resolve buffer overflow causing gem installation issues.
  • ruby-1.8.7-syck-avoid-buffer-overflow.patch
  • Resolves: rhbz#834381