Forge Fluid System!

Complete overhaul of the Liquid system in Forge.

-Fluids are now their own class (analog:Item) with properties.
-Fluids must be registered with the FluidRegistry - no exceptions.
-FluidStacks no longer have a meta for ID.
-Fluids save to NBT as a String, convert to an integer for packet purposes on reload.
-Fluid IDs are automatically synced on client login.
-FluidContainerRegistry now allows for the registration of simple containers that do not have an empty container ItemStack.
-Advanced Fluid containers can be created using the new IFluidContainerItem interface.
-IFluidHandler replaces and simplifies ITankContainer. Tanks can no longer be directly accessed.
-An extensible Fluid Block system, complete with render, has been added.
-A new interface for FluidBlocks (IFluidBlock) has been added. It should be called by pumps and the like.
-Reference implementations for basically everything.

Signed-off-by: King Lemming <kinglemming@gmail.com>