Implement Items Decay

[Gvin]

Items in all inventories should decay.
Decay rate depends on item and "decaying" should be shown on item icon in inventory.
The player should be able to see how much time is left for the item to completely decay in details panel for the item and in the item's tooltip.
After decaying completely the item should be deleted from the inventory and replaced with it's "decayed" item. Some items may not have "decayed" item so they should be simply removed.
Journal message should be added when the item has decayed completely in player's inventory (not in the storage).

Items in storage inventory decay at X0.75 rate (storing food in a good place is better that carrying it around with yourself).
Items on the ground decay X3 faster.

Items on the ground also have disappearing date assigned to them when dropping on the ground. It is not displayed anywhere. When this date is reached the item will be removed from the ground inventory. This is done to get rid of non-decaying trash that player can stack in some locations (unneeded search results, side products, etc.). There should be a message on ground inventory warning player about this effect.