Only use the EnergyNet-related interfaces if IC2 itself is loaded.
Also add some extra safety to useIC2().
Conflicts:
	src/main/java/mekanism/common/util/MekanismUtils.java
Shuffle up EnergyNet support a bit.
Remove the ENet's TileEntity instead of the world's one, and remove the existing one if one exists when adding the current one. Also move registration to on first tick to hopefully avoid adding too early issues. This is when IC2's delegates register so should be relatively foolproof.
Conflicts:
	src/main/java/mekanism/common/tile/TileEntityElectricBlock.java
Update IC2 api
ElectricBlocks now output to IC2 properly.
Prevent IC2 double-outputting.