Update closure-compiler.js

add multi modules compress function to closure-compiler.demo:
"closure-compiler": {
		all_in: {// can only compress to one file
		  closurePath: './',
		  js: ['dist/concat/Pre.js','src/js/Three.js'],
		  jsOutputFile: 'dist/min/Pre.js',
		  maxBuffer: 500,
		  options: {
			compilation_level: 'ADVANCED_OPTIMIZATIONS'
		  }
		},
		my: {//multi modules compress
		  closurePath: './',
                  maxBuffer: 500,
		  options: {
	            compilation_level: 'ADVANCED_OPTIMIZATIONS',
		module_output_path_prefix: "dist/min/modules/"
		  }
		  modules:[
		   {
		  	 js: 'src/js/Three.js',
		 	 jsOutputFile: 'Three'       //module name & filename
			 },
		  {
		  	 js: "dist/concat/parts/Pre.js",
		 	 jsOutputFile: 'Pre',
			 dependence:"Three"		//name of depended module 
			 }]}