Block Envy

Adds the following blocks to 1.7.10, includes slab and stair variants

World generation of Diorite, Andesite, and/or Granite can be controlled independently by configuration file

• Diorite
• Andesite
• Granite
• Claystone   (* a new block made from hardened clay and end stone)
• Polished Obsidian
• Polished Netherrack
• Polished Packed Ice