Fix item movement
Fix item movement

Moving an item inside showcases still seemed to succeed even if MoveItemBeforeMove
returned false. In reality the item would have been lost if the target position
was occupied. This has been fixed. The item is now moved back to it's source
location when MoveItemBeforeMove returns false.

Illarion-eV/Illarion-Server,Illarion-eV/Illarion-Server,Illarion-eV/Illarion-Server