Display trade-confirmations on Steam

[Pandiora]

Add an option to settings to display the confirmations right on steams website. Could be risky in terms of security - need to reevaluate this option. Low priority.

[Pandiora]

Lowering the priority due to not being as critical as refurbishing the app currently. I need to search for a secure approach, like Iframe. Problem with Iframe is that it either needs to be sandboxed and then communicates via special onmessage-listener or it must be secured in another way.