Update Scalar-List-Utils to CPAN version 1.39

  [DELTA]

1.39 -- 2014/06/05 15:54:59
  [CHANGES]
   * Have pairs() return blessed objects that recognise ->key and
     ->value as well as being two-element ARRAYs
   * Booleanise the result of looks_like_number() so as not to
     accidentally leak abstraction (RT94806)
   * Document the version each function was added in (RT96220)

  [BUGFIXES]
   * Try to preserve UV precision in sum() where possible (RT95902)
   * Document known lexical capture in pairmap bug RT95409
   * SvGETMAGIC() in set_prototype() (RT72080)