Allow ore to be smelted from accessible containers

[Vlek]

Currently cannot smelt directly from a pack animal. Don't make me work any harder than I have to.

Will need to check to ensure we can smell if:

• The ore is in the backpack (or child container thereof)
• On the ground
• On the ground in a container (again, or child container)
• On a pack animal (or a container...)

[Vlek]

Fixed in #112