convert nums to zh_cn

```
function getCode(num) {
    num = (num + '').split('');
    var map = {0: '', 1: '一', 2: '二', 3: '三', 4: '四', 5: '五', 6: '六', 7: '七', 8: '八', 9: '九', 10: '十'};
    var _map = {0: '', 1: '十', 2: '百', 3: '千', 4: '万'};
    var now;
    var index = 0;
    var re = []; 
    while((now = num.pop())) {
        if (+now) {
            re.unshift(map[now] + _map[index]);
        }   
        else if (index) {
            re.unshift('零');
        }   
        index++;
    }   
    return re.join('').replace(/^一十/, '十').replace(/零+/, '零').replace(/零$/, '');
}

// angular封装filter
angular.mobule('app').filter('toCN', function () {
  var filter = function (num) {
    num = (num + '').split('');
    var map = {0: '', 1: '一', 2: '二', 3: '三', 4: '四', 5: '五', 6: '六', 7: '七', 8: '八', 9: '九', 10: '十'};
    var _map = {0: '', 1: '十', 2: '百', 3: '千', 4: '万'};
    var now;
    var index = 0;
    var re = []; 
    while((now = num.pop())) {
        if (+now) {
            re.unshift(map[now] + _map[index]);
        }   
        else if (index) {
            re.unshift('零');
        }   
        index++;
    }   
    return re.join('').replace(/^一十/, '十').replace(/零+/, '零').replace(/零$/, '');
  };
  return filter;
});
```
```
// 用法
<div>{{test | toCH}}</div>
```