bootstrap-datepicker 插件修改为默认中文

datepicker插件默认为英文，而且格式为：mm/dd/yyyy这种情况，看起来不怎么直观。

修改目标：

1、默认显示为中文  

2、格式为：yyyy年mm月dd日

需要修改两个地方：

1、更改datas对象， 增加zh-cn语言选项；参见源代码的1419行

var dates = $.fn.datepicker.dates = {
        en: {
            days: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"],
            daysShort: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"],
            daysMin: ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"],
            months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
            monthsShort: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
            today: "Today",
            clear: "Clear"
        },
        "zh-cn":{
            days: ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"],
            daysShort: ["周日", "周一", "周二", "周三", "周四", "周五", "周六", "周日"],
            daysMin: ["日", "一", "二", "三", "四", "五", "六", "日"],
            months: ["一月份", "二月份", "三月份", "四月份", "五月份", "六月份", "七月份", "八月份", "九月份", "十月份", "十一月份", "十二月份"],
            monthsShort: ["一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月"],
            today: "今天",
            clear: "清空"
        }
    };
    
     红色部分为新增部分。

        2、修改默认参数，即defaults对象。       

var defaults = $.fn.datepicker.defaults = {
        autoclose: false,
        beforeShowDay: $.noop,
        calendarWeeks: false,
        clearBtn: false,
        daysOfWeekDisabled: [],
        endDate: Infinity,
        forceParse: true,
        format: 'yyyy年mm月dd日',
        keyboardNavigation: true,
        language: 'zh-cn',
        minViewMode: 0,
        multidate: false,
        multidateSeparator: ',',
        orientation: "auto",
        rtl: false,
        startDate: -Infinity,
        startView: 0,
        todayBtn: false,
        todayHighlight: false,
        weekStart: 0
    };

       3、效果如下