Playlist product image is not deserialised properly if posted in json

[danhaller]

The image property of a playlist product has a property name of "ImageUrl" when the Playlist API expects "image". This is correctly handled with an XmlElement attribute for xml, but there is no equivalent json attribute.

This means that if the wrapper is used to post playlist updates with a json payload, the image does not make it to the API.

I plan to fix this now by adding the missing attribute.

[danhaller]

I'm going to hold off on this one, because the playlist API itself doesn't currently support this