Deactivate active items when completely unloaded.

Fixes #10123 - the message is not shown when the ammo is a liquid, as that would be a bit complicated (unloading can be canceled if the player refuses to select a container). The "select container from inventory" window should be message enough.

Fixes #10194 - The flashlight would go off after some turns. It only consumes charges every 15 turns, and only than the charges are checked and found to be 0. However, this PR adds an explicit call to invoke the items iuse function to deactivate it (just like manually deactivating it).
Workable.  Next fix is to have it say that the item turns off on its own, rather than "you turn your X off" as folks are probably gonna think it's a bug.