Speed up very elemental functions

[DNF]

@stillyslalom

@btime vmap(V) do v # LoopVectorization
           energies_spin(v, 2.0,1.0,0.0,0.0,1.9,0.0,1)
       end setup=(V = rand(1000))

You can also try @tturbo or @turbo:

@tturbo out .= energies_spin.(...

It seems to be a bit slower than vmap/vmapntt! for some reason. But still dramatic speedup (20-30x on my 6-core machine.)