Release 0.159.0

Bugs fixed:

• Fixed clang 11 compile issues #284
  and #285.

Changes:

• In the jsonpointer extension, the type names json_ptr and wjson_ptr have been deprecated and
  renamed to json_pointer and wjson_pointer.

Enhancements:

• The json_pointer operators /= and / now support integers.

• New override for jsonpath::json_replace that searches for all values that match a JSONPath expression
  and replaces them with the result of a given function, see #279

• New factory function jmespath::make_expression to create compiled JMESPath expressions.