Uc 44 Marketing email opt in

Adding marketing opt-in checkboxes to the facebook modal and the signup form.

The state of the checkbox is different depending on where the user is located. If they are in Canada, the checkbox is visible and unchecked. If they are in Europe, the checkbox is visible and checked. Anywhere else, the checkbox is hidden and checked. 
@lizlux is there a reason you're lower casing the continent and country codes here? I just did a quick geo edge test in a few different continents and countries (including Europe and Canada), and they all came back up case so you shouldn't have to normalize their case. Considering they're abbreviations, leaving them upper case also makes more sense to me.