remove type piracy from show of DoubleFloat types (#179)

Author: KristofferC

src/type/show.jl

@@ -1,8 +1,5 @@
 import Printf: ini_dec, fix_dec
 
-show(io::IO, ::Type{Double64}) = print(io, "Double64")
-show(io::IO, ::Type{Double32}) = print(io, "Double32")
-
 function show(io::IO, x::DoubleFloat{T}) where {T<:IEEEFloat}
     compact = get(io, :compact, false)
     if compact