Improve Inventory's items drag and drop.
Modify Inventory's items drag drop image position
Add ground shadow to sprites elements
Cap shadow in lightmap ( index 7 isn't used )
Implement picking priority (if the mouse is over two entities, we need to focus on the more important). Player < NPC < ITEM < Monster
Fix Camera lerp.
If the game don't render for some seconds (minimize window for example), the camera will jump far away.
Inventory's items can now be throw on the map (drag and drop)