Progress on Vertical Dungeon Clipping (broken)

Changed SchematicLoader to use new dimHelper functions to move links
around. This should have allowed us to shift dungeons safely.
Unfortunately, Minecraft still crashes, so the link functions aren't
working as advertised. Please figure out what's going on. >_< The code
is done, it's just link issues that prevent it from working.
Merge pull request #62 from SenseiKiwi/master

Progress on Vertical Dungeon Clipping (broken)