switch to Unitful.jl?

[tbenst]

From #14 (comment), I see that switching to Unitful.jl was once (still is?) considered. Barring that, I'm wondering if there's a way to convert eg mm into inches?

For example, with Unitful: uconvert(u"inch",183u"mm"), or simply import Unitful: mm, inch; uconvert(inch,183mm).

How to do this right now in case it helps a stray Julian:

using Measures, Unitful
W = 200mm
uconvert(u"inch",Quantity(W.value,u"mm"))