Update JSON-PP to CPAN version 2.94

Update JSON-PP to CPAN version 2.94

  [DELTA]

2.94  2017-05-29
    - fix a test to support perl 5.6

2.93  2017-05-15
    - fix packaging issue

2.92  2017-05-15
    - production release

2.91_04  2017-01-10
  - fixed isa tests for bignum

2.91_03  2017-01-09
  - reworked documentation, based on the one for JSON::XS
  - let json_pp utility to show the version of JSON::PP
  - applied a patch to fix loading order of B module (pali++)

2.91_02  2016-12-04
  - fixed not to fail tests under Perl 5.25.* (srezic++)

2.91_01  2016-12-03
  - changed the number detection logic, patched by haarg
    (experimental)
  - merged PR from dagolden to correct 0 handling
  - removed base.pm dependency (dolmen)
  - fixed wrong character offset spotted by ilmari
  - applied patches from Jarkko Hietaniemi to address VAX issues
  - small doc fixes from bessarabov, gregoa, Chris Anderson
  - applied a patch to remove . in @INC in json_pp (Tony Cook)
  - removed $VAR1 from json_pp output, spotted by tokuhirom
  - fixed an issue to ignore trailing 0
  - added Scalar::Util dependency for Perl 5.8+
  - fixed issues spotted by Nicolas Seriot's JSON Test Suite
    including experimental UTF-16/32 support and backward
    incompatible change of C style comment handling (now disabled
    by default)
  - moved the guts of JSON::PP::Boolean into lib/JSON/PP/Boolean.pm
    and gave it a proper version
  - refactored incremental parser to let it handle incomplete
    JSON text properly
  - imported and tweaked tests from JSON.pm
  - minor code clean up