Update __init__.py

Put "United States" at the head of the list, which will make it a default for credit cards.
Merge pull request #1802 from vielmetti/master

Fix #1175, make default credit card country "United States".
use Chosen for country select on credit card form

this is a follow-up to #1802
fix width issues on credit card form
Merge pull request #1803 from gittip/ui/chosen-for-credit-card-form

use Chosen for country select on credit card form