LimitOrder.Size should be double? not simple double.

[GeoffTyrer]

I was using the BetTargetType/BetTargetSize way of using placeOrders and it was throwing an exception everytime I made the call. Turns out it's because Size shouldn't be featured in the JSON. So I made Size nullable and the problem went away. This isn't an issue when using placeOrders in the regular way becasue Size is obviously needed - but with BetTargetType/Size it isn't. Hope this helps and thanks for all the work you've put into this. Geoff Tyrer