improve ghoststones, speed too

I remembered twoelk's menger sponge on VaE's server and that he tried to surround it with ghoststones but it didn't work because of recursion, I think, so I edited the ghoststones that they can't be used as a mesecons connection and I improved speed: voxelmanip is used if very much(>49) ghoststones are used.
I don't know exactly how the current mesecons works, this ghoststone change may stopped using a recursive function.