moonwalk一个简单的事件驱动的Node目录树Walker

月球漫步是一个简单的事件驱动的目录树walker。用法示例：

// This program walks all files and directories under /home/sixpounder

var Moonwalker = require('moonwalk');

var m = new Moonwalker('/home/sixpounder');

m.on('file', function (path) {

  console.log('Found file: ' + path);

});

m.on('directory', function (path) {

  console.log('Found directory: ' + path);

});

m.on('end', function () {

  console.log('Walking completed!');

});