message: get file extension when no extension
diff: @@ -163,7 +163,9 @@ namespace util
  //! gets the file extension (ignoring case)
  inline std::string getFileExtension(const std::string& filename) {
  - std::string extension = filename.substr(filename.rfind(".") + 1);
  + size_t pos = filename.rfind(".");
  + if (pos == std::string::npos) return "";
  + std::string extension = filename.substr(pos + 1);
  for (unsigned int i = 0; i < extension.size(); i++) {
  extension[i] = tolower(extension[i]);
  }
  