Update Encode to CPAN version 2.56

  [DELTA]

$Revision: 2.55 $ $Date: 2013/09/14 07:51:59 $
! Encode.pm t/Encode.t
  Merged RT#91569: [PATCH] decode_utf8 and non-PVs
  https://rt.cpan.org/Ticket/Display.html?id=91569