Currently we have https://metabrainz.org/payment where customers can make payments to our US PayPal account. I've created a PayPal ES account and we need to start accepting payments for both EUR and USD on our site.

This entails 3 things:

1. Turn https://metabrainz.org/payment into a disambiguation page that tells people to go to the EUR or USD specific page, with links to both of them.
2. Add https://metabrainz.org/payment/usd which should basically contain everything that the /payment page currently contains.
3. Add https://metabrainz.org/payment/eur which should be the same as the usd page, but use our ES paypal account.

The same process should be applied to /donate which then goes to /donate/usd and /donate/eur mirroring the process of the payment system.