Items can get stuck dragging in inventory
- Start dragging an item (hold down)
- Move the mouse to a gutter in the inventory grid
- Release the mouse
- The item will continue following the mouse instead of being moved
- Clicking on an occupied slot will leave a 'ghost' of the item without actually moving the item
- Clicking on an empty slot will correctly move the item
When this happens, the item should probably be put in the last-hovered slot (the one with the hover class still attached -- dragging an item into a gutter doesn't un-hover the slot it was last hovering)