Using outer class variables with TradeCommands.
Taking advantage (?) of accessing outer class variables from TradeCommands, reducing the need for a duplicate trade URL session token and login token.
Made fields in TradeInternalItem package private, added getters.
It's not like we should ever have direct access to them, right?
Merge branch 'master' of https://github.com/nosoop/SteamTrade-Java.git