Update Dungeon Loot and Config Options

1. Made World Thread available as dungeon loot
2. Removed useless config options for loot that doesn't appear anymore
3. Tweaked some config names and variable names for consistency
Merge remote-tracking branch 'upstream/master'
Added Ender Pearls as Loot

Added a 30% chance of Ender Pearls appearing in grave chests.
Changed Crafting Recipes

Changed crafting recipes to always use Stabilized Fabric instead of
Ender Pearls.
Updated Stabilized Rift Signature

Modified the Stabilized Rift Signature to consume Stable Fabric instead
of Ender Pearls.
Changed Rift Blade Recipe and Power

Changed Rift Blade recipe to use Stable Fabric and a Blaze Rod. Changed
its base material from Gold to Diamond, which increases attack power and
decreases enchantability a little.
Minor Changes

Minor spacing changes to BaseDimDoor.
Started Adding Heads to Grave Chests

Started adding heads to grave chests in dungeons. We currently only
spawn skeleton heads as a test.
Merge remote-tracking branch 'upstream/master'
Added Config for Corium

Added a line in our config file for setting the block ID of Corium. Even
though it's only temporary code that's going to be removed later, people
need that to run our dev builds properly.
Merge pull request #128 from SenseiKiwi/master

Various Updates