message: Added get_all_mappings() function to LandmarkMapper
  This is useful if one wants to retrieve all the loaded mappings from the mappings file.
diff: @@ -130,11 +130,18 @@ public:
  *
  * @return The number of landmark mappings.
  */
  - auto num_mappings() const { return landmark_mappings.size(); };
  + auto num_mappings() const {
  + return landmark_mappings.size();
  + };
  +
  + const auto& get_all_mappings() const {
  + return landmark_mappings;
  + };
  private:
  - std::unordered_map<std::string, std::string>
  - landmark_mappings; ///< Mapping from one landmark name to a name in a different format.
  + std::unordered_map<std::string, std::string> landmark_mappings; ///< Mapping from one
  + ///< landmark name to a name
  + ///< in a different format.
  };
  } /* namespace core */
  