Add Option to Present a Form Field's Options in a Popover in iPad Apps

Add UIPopoverController option for displaying form field options; add FXFormFieldPopover property country and gender form fields; add every country code to the country form field option list to show how large lists are handled in popover

Note's for Nick:
- I had to make the CustomFormControllerExample a Universal app so that it could be run as an iPad app as well. This caused it to upgrade it to 7.1, but maybe an option to downgrade that a bit. 
- Runs great in iPad and is ignored in iPhone.