JS for replacing submit buttons with 'Saving' throbber broken in D7

I have to admit I'm guilty of stealing the JS/throbber for replacing submit/save buttons with a throbber/saving message for half my projects (to prevent duplicate form submissions). I needed it for a D7 project today, so I reformatted the jQuery for Drupal 7 standards (had to add in a couple divs, for the comment form, rename the selector for the user-register-form, and reformat the code to follow D7 JS coding styles.

I will attach the patch against the 7.x-2.x branch in the comment below.