Submit button disabled, styled gracefully

This PR:

- Removes the css animation we had as a "submitting state" 
- Replaces it with a more basic "disabled style" that still uses copy to inform the user the form is being submitted
- Applies these styles in-line, to route around some difficulty rendering styles as the form was being POSTed.
- Has been tested on iPad/iPhone, Android devices via Chrome's new devtools.