Release 0.156.0

Bugs Fixed:

• Fixed issue with JSONCONS_N_MEMBER_NAME_TRAITS macro, \263

Enhancements:

• New basic_json(json_const_pointer_arg_t, const basic_json*) constructor to
  allow basic_json values to contain non-owning views of other basic_json
  values.

• New deep_copy function to make a deep copy of a basic_json value that
  contains non-owning views on other basic_json values.

• Reduced memory allocations in the jmespath extension using the new
  basic_json(json_const_pointer_arg_t, const basic_json*) constructor.

• Support for encoding std::bitset into base16 encoded strings (JSON) and
  byte strings (binary formats), and decoding std::bitset from integer values,
  byte strings and base16 encoded strings.

• Support 128 bit integer types __int128 and unsigned __int128, if supported
  on the platform.