整理代码，将节点路径提出。

Author: wangxiao

lib/utils.js

@@ -6,6 +6,12 @@ var _ = require('underscore');
   XMLHttpRequest: false, XDomainRequest: false, exports: false,
   require: false */
 module.exports = function(AV) {
+
+  var config = {
+    cnApiUrl: 'https://leancloud.cn',
+    usApiUrl: 'https://us-api.leancloud.cn'
+  };
+
   /**
    * Contains all AV API classes and functions.
    * @name AV
@@ -71,9 +77,6 @@ module.exports = function(AV) {
     return child;
   };
 
-  // Set the server for AV to talk to.
-  AV.serverURL = "https://api.leancloud.cn";
-
   // Check whether we are running in Node.js.
   if (typeof(process) !== "undefined" &&
       process.versions &&
@@ -147,20 +150,22 @@ module.exports = function(AV) {
     };
   }
 
-
    /**
     *Use china avoscloud API service:https://cn.avoscloud.com
     */
-   AV.useAVCloudCN = function(){
-    AV.serverURL = "https://leancloud.cn";
-   };
+  AV.useAVCloudCN = function(){
+    AV.serverURL = config.cnApiUrl;
+  };
 
-   /**
-    *Use USA avoscloud API service:https://us.avoscloud.com
-    */
-   AV.useAVCloudUS = function(){
-    AV.serverURL = "https://us-api.leancloud.cn";
-   };
+  /**
+  *Use USA avoscloud API service:https://us.avoscloud.com
+  */
+  AV.useAVCloudUS = function(){
+    AV.serverURL = config.usApiUrl;
+  };
+
+
+  AV.useAVCloudCN();
 
   /**
    * Returns prefix for localStorage keys used by this instance of AV.
@@ -422,7 +427,7 @@ module.exports = function(AV) {
       return AV._getInstallationId();
     }).then(function(_InstallationId) {
       dataObject._InstallationId = _InstallationId;
-      
+
       var data = JSON.stringify(dataObject);
       return AV._ajax(method, url, data).then(null, function(response) {
         // Transform the error into an instance of AV.Error by trying to parse
@@ -552,8 +557,9 @@ module.exports = function(AV) {
     if (value.__op) {
       return AV.Op._decode(value);
     }
+    var className;
     if (value.__type === "Pointer") {
-      var className = value.className;
+      className = value.className;
       var pointer = AV.Object._create(className);
       if(value.createdAt){
           delete value.__type;
@@ -566,7 +572,7 @@ module.exports = function(AV) {
     }
     if (value.__type === "Object") {
       // It's an Object included in a query result.
-      var className = value.className;
+      className = value.className;
       delete value.__type;
       delete value.className;
       var object = AV.Object._create(className);