Fixed indent

Added Stat save/load
New features

This version is not fully completed.
[FEATURE] Added graphical menus for buy and sell.
[FEATURE] Added discount coupons.
[FEATURE] Added the possibility to sell items while paying, performing a trade.
[CODE] Renamed classes with appropriate names.
[CODE] Added langpack strings.
[BUG] You can't build a Coupon item right now.
and many other things
Bugfix for coupons

Fixed coupon appliance
Fixed item trading
Added item trading when paying
[BUG] you can trade items that you don't own (near fixing)
and other fixes
Last update license