Fixed addListener for onFormSubmit

When adding an onFormSubmit listener via the addListener interface, the listener was not added properly.

There is currently no test case for this, by the way.
Reflected previous fix in the minified Files
Corrected test case for addListener/onFormSubmit.

It was previously passing a nested object instead of a shallow one.
Merge pull request #72 from catearcher/patch-1

Fixed addListener for onFormSubmit