The Functional Sheep release

Certain sheep now have behaviours associated with them:

• Redstone Sheep will trigger redstone signals
• TNT Sheep will explode if exposed to redstone
• Glowstone Sheep will light the area around them
  • This is disabled by default because of the stuttering of it recalculating chunk lighting.
• Chisel blocks with "working" fans cause sheep to fly
• Crafting Table sheep work as crafting tables
• Anvil sheep work as Anvils
• Cactus sheep deal cactus damage and will destroy items
• Magma sheep deal "walking on fire" damage.

In addition to this the following other enhancements were made:

• Chiseling a sheep gives audio feedback
• Added a preliminary API. This is subject to change and will be documented when I'm happy with it.