code: function serveFileOrDie(req, res, gameInfo, cb) {
      var filePath, file;
  
      file = getFileFromReq(req, res);
      if (!file) return;
  
      if (file === '*') {
          zipResults(req, res, gameInfo);
          return;
      }
  
      // Build path to file.
      filePath = cb(file);
  
      fs.exists(filePath, function(exists) {
          if (!exists) {
              res.status(404).send('File not found: ' + file);
              return;
          }
          else {
              res.sendFile(filePath);
          }
      });
  }
docs: ### serveFileOrDie
  
  Analizes the request object and sends the requested file or a 404 error
  
  @param {object} req The request object from Express
  @param {object} res The respond object from Express
  @param {object} gameInfo The game info as in channel
  @param {function} cb A callback function that adjusts the path to
  the requested file (files can be also outside of the game directory)
  
  @see getFileFromReq