message: core: add getcwd() stub
diff: @@ -563,6 +563,7 @@ cv::String getCacheDirectory(const char* sub_directory_name, const char* configu
  cv::String canonical(const cv::String& /*path*/) { NOT_IMPLEMENTED }
  bool exists(const cv::String& /*path*/) { NOT_IMPLEMENTED }
  void remove_all(const cv::String& /*path*/) { NOT_IMPLEMENTED }
  +cv::String getcwd() { NOT_IMPLEMENTED }
  bool createDirectory(const cv::String& /*path*/) { NOT_IMPLEMENTED }
  bool createDirectories(const cv::String& /*path*/) { NOT_IMPLEMENTED }
  cv::String getCacheDirectory(const char* /*sub_directory_name*/, const char* /*configuration_name = NULL*/) { NOT_IMPLEMENTED }
  