Fix anomally of year spans generation

In my application I enable and disable datepickers on the same page constantly, and an issue came up where the year spans were not being generated, I singled it down to this line being `end()` wasn't working with jQuery@2.1.1

I don't know why, but this is how I fixed my own issue, if someone else has this issue later it is now documented.

![image](https://cloud.githubusercontent.com/assets/2925395/3750149/f8ea6c9c-17f2-11e4-9dfb-e9ac6c269cc3.png)