@ashfurrow => bids, countdowns and bid previews

* Adds the logic to place a bid, as I couldn't get the RAC signal passing to work I've just left it in a broken state. It will run through a lot of the networking to place a bid - but not all.

* Adds a countdown to the end of an auction. The Auction we work off has a broken end date, so it wil lalways show "closed" until it's fixed.

* Most fulfillment view controllers now have a bid preview at the top of the view

* Consolidates the artwork title and date to an attributed string that uses the standard formatting

*  Move a few tests to pending as I couldn't figure out why it was raising an exception or never looking like it was meant to.
Sorry, I mistyped. The signal sends `true` if the number is of zero length, right? So calling it `numberIsValid` signal is a little weird.