// 例如：将下面数据
[
    ["a", "aa", "aaa", "aaaa"],
    ["b", "bb", "bbb"],
    ["a", "ab", "aba"],
    ["a", "aa", "aab"]
] 
// 转为：
[
    {
        "name" : "a",
        "child" : [
            {
                "name" : "aa",
                "child" : [
                    {
                        "name" : "aaa",
                        "child" : [
                            {
                                "name" : "aaaa",
                                "child" : []
                            }
                        ]
                    },
                    {
                        "name" : "aab",
                        "child" : []
                    }
                ]

            },
            {
                "name" : "ab",
                "child" : [
                    {
                        "name": "aba",
                        "child" : []
                    }
                ]

            }
        ]
    },
    {
        "name": "b",
        "child" : [
            {
                "name" : "bb",
                "child" : [
                    {
                        "name" : "bbb",
                        "child" : []
                    }
                ]
            }
        ]
    }

]