receive_date on paypal contribution should be taken from IPN

So, this is a bit obscure. We had a paypal recurring profile where the first transaction failed. The second transaction succeeded but because it was the 'first' successful contribution it took the original contribution but left the date the same - as the failed first one. Leaving us with an incorrectly dated contribution.

While I would argue that the first failed contribution should be visible in the DB I'm going to limit this ticket to ensuring the payment date passed from paypal is the receive date - paypal pro passes it back as

"payment_date":"07:02:02 Oct 10, 2013 PDT"