63 image compression

- This PR should conform to our feature branch > rebase > PR workflow
- This PR contains javascript that needs to be refactored into its own file, and currently is loaded via index.erb. If this is grounds for rejection, that's fine.
- The JS implements a feature creating proportionally consistent, smaller versions of images uploaded by the user. A new FileData object is then used to collect and group these new small image and data entered into the  form's text fields. 
- An XHR request is used to pass that data to the server, and prevent the default submission of the form.
- On success of that XHR request, we use window.location to route the user to /applications. This may or may not be a sufficiently intelligent way to redirect the user.
- We use the simplest loading animation possible on submission, which is a "loading" state for buttons that comes off the shelf with bootstrap.