code: function( replace , dest ){
  		var _buffer = [],
  			_url,
  			_code,
  			_files  = replace.css;
  		for( var i = _files.length; i--; ){
  			_url 	= config.dir.src_dir + _files[ i ];
  			if( grunt.file.exists( _url ) ){
  				_code = tool.fix_image_url( grunt.file.read( _url ).toString() , _url );
  				_buffer.push( _code );
  			};
  		};
  		_code = new mincss( config.mincss ).minify( _buffer.join( "" ) );
  		grunt.file.write( dest , _code );
  	}
docs: /*!
  压缩文件
  @replace 	{object} 	replace 的配置文
  @dest 		{string} 	保存的目标地址
  return  	{string}