Allow for light values above 1 and below 0 in Minecraft

[ExE-Boss]

The way this would be achieved is through a Minecraft Block where the metadata would specify if the block increases or lowers the light value.

Additional functionality could be added to this block later.

The block would have the following metadata values:

• 0: Block has a light value of 15 and lets light through fully and has no collision (what mods do to achieve flood lights, ex. Thaumcraft and Factorization lamps)
• 1: Block has a light value of 0 and subtracts 1 from the light that passes through it (like leaves) and has no collision