Abstract Microfloat type

[AntonOresten]

Microfloat is currently a primitive type with a trait-ish variant type parameter for defining different behaviors. An alternative is making abstract type Microfloat{S,E,M} <: AbstractFloat end , and requiring primitive subtypes like to implement the methods instead, i.e. primitive type MXFloat{S,E,M} <: Microfloat{S,E,M} 8 end. This is a little more Julian, but primitive types don't feel as user friendly, and I think it's cool to be able to subtype other variants in the type parameter version... not that it's really needed, and defining something like the MX types are just a few dozen lines anyway.

[AntonOresten]

Perhaps move the variant type parameter to the front. Makes it easier to define methods that dispatch on like Microfloat{<:MX}, allowing for easy subtyping of MX to inherit those methods.