Fix volume units

Hey this is just replacing the Megalitres with Kilolitres. Megalitres are huge! like for measuring reservours. I doubt anything will ever be sold in those, even Kilolitres really...

But people keep selecting ML instead of mL and it's pretty amusing explaining the problem with that to them. 

Hopefully I got them all properly, I'm pretty sure... but seems like this shouldn't be set in so many places either, maybe we should template them into the js from rails variables.