AMD研究，组件的动态加载。

研究了一下dojo的ADM。明白组件的加载机制了。

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dom.js

fu.define([], function(){
	return {dom:"dom"};
});

string.js

fu.define([], function(){
	return {"string" : "string"};
});

on.js

fu.define([], function(){
	return {on:"on"};
});