Make fluid values integers

[Zakharov]

Fluids don't currently interact very well with the circuit network, and trying to use the circuit networks to allow multiple fluids to flow through the same pipes is a huge pain. The new fluid wagons can only ever carry one type of fluid, because pumping out all the fluid leaves "0.0" left, which blocks any other kind of fluid from being pumped into the wagon. Since all fluid values have just been multiplied by 10, it would be really easy to just round all fluid values down to the nearest integer.

[roberwt]

I'm not a developer, but as far as I know, is it not possible to change variable types without serious recoding. I think the issue isn't big enough for that.

[aober93]

Floats can also be rounded while still being floats.