Items: Fuel Cans should be usable for target practice (and explode)

[MrFrank]

As it says in the title. Fuel Cans can now be set up as a target (or dropped) and can be shot at with ranged weapons or spells.

In addition, on successful hit, they explode and deal minor AoE fire damage in the area, potentially including the target shooter themselves. It could be as little as 5/25 or something similar, I'm not sure on exact numbers.

Got the idea from playing Left 4 Dead

[kylinn]

Heck, we could do something similar way back in "Doom" in the 90s. I vote yes, based on "cool flavor and utterly reasonable"