madrobby/zepto — pull request #771 by woc2006 (2013-06-20 06:56:42+00:00)
Title: $.param fix for sparse array

$.param run to an error with a array like this:
```javascript
var arr = [], arr[5] = 1, arr[10] = 2, arr[15] = 3
var result = $.param(arr)
```
**Error: name is undefined**
Here is a simple fix.