code: function crawlDirectoryWithFS(parent, sync) {
      return fsCmd('readdir', sync, parent).then(function (things) {
          return Q.all(things.map(function (file) {
              file = path.join(parent, file);
              return Q.all([file, fsCmd('stat', sync, file)]);
          }));
      }).then(function (stats) {
          return Q.all(stats.map(function (args) {
              var file = args[0], stat = args[1];
              if (stat.isDirectory()) {
                  return crawlDirectoryWithFS(file, sync);
              }
              return file;
          }));
      }).then(function (grouped) {
          return [].concat.apply([], grouped);
      });
  }
docs: Recursively crawl a directory for all of it's files.