Release 0.172.0

Defect fixes:

• Fixed issue #469 affecting JSMESPath expressions with terminating CR

Enhancements to jsonpath

• Added result_option sort_descending.

• Added new classes basic_json_location, basic_path_element, and basic_path_node.

• Added a new function get for selecting a single JSON value from a JSON document at
  a location represented by a json_location.

• Added a new function remove for removing a single JSON value from a JSON document at a
  location represented by a json_location.

• Added member function select to jsonpath_expression.

• Added member function select_paths to jsonpath_expression.

• Added member function update to jsonpath_expression, to support
  update-in-place for compiled JSONPath expressions.

Enhancements to jsonpointer:

• Added free functions to_string and to_wstring.

• Added append function to basic_json_pointer.