Log Message:
Update to 4.00

Upstream changes:
4.00 2018-12-07
    - production release

3.99_01 2018-12-03
    - BACKWARD INCOMPATIBILITY:
      As JSON::XS 4.0 changed its policy and enabled allow_nonref
      by default, JSON::PP, and thus JSON, also enabled allow_nonref
      by default

    - updated backportPP with JSON::PP 3.99_01
    - allow PERL_JSON_PP_USE_B environmental variable to restore
      old number detection behavior for compatibility