Dom pollution

I use Autosize plugin to control size of an in-place input control. I create `<input>` dynamically each time user clicks on editable data.

Autosize dutifully creates a mirror `<span>` each time — and does not destroy it when an input is destroyed. 

Here is a fiddle to reproduce the problem: http://jsfiddle.net/c1fxnezx/

I can contribute a fix if you'll tell me which way you want me to fix it.
