Changed to compile on save.
Renamed TradeErrorCodes to TradeStatusCodes.
Changed trade status number to integer.
(I don't think we'll be getting really high values of that.)
Smoothed handling of Steam Trade error status codes.
Also made some classes final.
Added documentation for trade status codes.
Adds passing of unknown trade events to the trade listener.
Added undefined error.
Changed visibility of constructors in the com.nosoop.steamtrade.status package.
Made the currency amount key optional (foreign inventories do not have it).
Reflected update in onError() method.
Modified onError() method to support detailed error messages.
Removed fireEventError() and added detailed error events for the TradeListener.