GenericInventory and SteamTradeDemoHandler FIXES

@GenericInventory
The change is a mispelling of the word "instanceid",
since this was
mispelled all instanceids were nulled. Somehow this fixed
it.

@SteamTradeDemoHandler
Note: most changes are made by Visual Studio
2012 itself so only check
the changed below this text:
public override
void OnTradeInit()
- added coupon support.

public override void
OnTradeAddItem(Schema.Item schemaItem,
Inventory.Item inventoryItem)
-
added bot log warn / error message when a tf2 item or steam item
is
added. Just for debugging.

public override void OnTradeAccept()
-
after trade is completed i fixed the error that people will get :
There
is already added an item with the same key
-- i did this with the usage
of the clear method to clear both
dictionaries (descriptions and
items)

public override void OnTradeClose()
- i added this method in the
steamtradedemohandler so that when the user
cancels the trade it also
clears the dictionaries as method above for
same reason.

If things
aren't clear  please let me know.

P.S. i've talked about the issues
before with gabrielmtzcarrillo