Added recommendation opt-out (bug 1072637)

![dhvqs0rfebww-xth-cxvcxtq6d8igl2gtaojiblmtmi](https://cloud.githubusercontent.com/assets/1106/4985257/959f4376-692b-11e4-8ca8-36b6b0f12878.png)
![screen shot 2014-11-10 at 14 46 53](https://cloud.githubusercontent.com/assets/1106/4985268/aba9d366-692b-11e4-9dc8-3342a9220cb6.png)

Yeah, the form had 2 fields and one was being removed so it didn't make sense to use `serialize`. Plus, `serialize` doesn't include unchecked checkboxes.