code: function findExtensions(dir, cb) {
    readDirs(dir, function(err, modules){
      checkModules(modules, function(err, extensions){
        parseModules(extensions, cb);
      });
    });
  }
docs: ### Locate Strider Extensions  Under a specified path **dir** look for directories containing file 'strider.json'.  These are considered Strider modules. **dir** may be either a string or a list of strings.  Or look for package.json with a "strider" key inside. (Preferred way now)  **cb** is a function of signature cb(err, extensions) where extensions is an {id : config} mapping on success and err is an error on failure.