gistfile1.js

   if (self._minifyTogether) {
      var sources = _.map(self.js, function (file) {
        return file.contents('utf8');
      });

      buildmessage.enterJob({title: "minifying"}, function () {
        allJs = _minify(minifiers.UglifyJS, '', sources, minifyOptions).code;
      });

      self.js = [new File({ info: 'minified js', data: new Buffer(allJs, 'utf8') })];
      self.js[0].setUrlToHash(".js");
    } else {
      minifyOptions.compress.unused = false;
      minifyOptions.compress.dead_code = false;

      var groups = {"packages": [], "templates": [], "main": []};

      _.each(self.js, function(file) {
        if (/packages/.test(file.info)) {
          groups['packages'].push(file);
        }
        else if (/template\./.test(file.info)) {
          groups['templates'].push(file);
        }
        else {
          groups['main'].push(file); 
        }
      });

      self.js = [];

      for (var group in groups) {
        allJs = buildmessage.forkJoin({title: "minifying" }, groups[group], function (file) {
          var source = file.contents('utf8');
          return _minify(minifiers.UglifyJS, file.info, source, minifyOptions).code;
        }).join("\n\n");

        var file = new File({ info: 'minified ' + group + ' js', data: new Buffer(allJs, 'utf8') });
        file.setUrlToHash("." + group + ".js");
        self.js.push(file);
      }
    }