Orcfort: Add Boneforge smelter

Extract blood, ironbone, bloodsteel, and wood burning labours
are all here. The relevant reactions have been moved from the
kitchen and totem pole.

Many thanks to shadowclasper for help with the building design.
http://www.bay12forums.com/smf/index.php?topic=134547.120

GH #110
Updated orc manual (Wiki version: 0f9d452)

This documents the boneforge.