Barrels 2012

*Barrels 2012* makes things from TerraFirmaCraft wearable on the player's back, similar to how it was in the Classic mod (ie, in 2012). The following things are wearable:

- Barrels - Large Vessels - Lamps (with dynamic light functionality) - Anvils - Powderkegs (just don't accidentally step on a fire!) - Crucibles