优化模块加载顺序，将旧模块放到最后。

Author: wangxiao

lib/av.js

@@ -16,7 +16,6 @@ AV.XMLHttpRequest = require('./browserify-wrapper/xmlhttprequest').XMLHttpReques
 AV.localStorage = require('./localstorage');
 
 // 以下模块为了兼容原有代码，使用这种加载方式。
-// The module order is important.
 require('./utils')(AV);
 require('./error')(AV);
 require('./event')(AV);
@@ -27,18 +26,21 @@ require('./relation')(AV);
 require('./file')(AV);
 require('./object')(AV);
 require('./role')(AV);
-require('./collection')(AV);
-require('./view')(AV);
 require('./user')(AV);
 require('./query')(AV);
-require('./facebook')(AV);
-require('./history')(AV);
-require('./router')(AV);
 require('./cloudfunction')(AV);
 require('./push')(AV);
 require('./status')(AV);
 require('./search')(AV);
 require('./insight')(AV);
 require('./bigquery')(AV);
 
-AV.AV = AV; // Backward compatibility
+// 以下模块是旧模块，与 core 版本的区别，准备去掉这些方法
+require('./collection')(AV);
+require('./view')(AV);
+require('./facebook')(AV);
+require('./history')(AV);
+require('./router')(AV);
+
+// Backward compatibility
+AV.AV = AV;