This technically introduces a regression with regards to the way that
modifier masks are printed in X.U.NamedActions and X.H.DebugEvents.
However, since this way of printing masks is move in line with
X.U.EZConfig, I personally don't think that this is noteworthy.
This is a convenience module in order to have less import noise. It
re-exports the following:
a) Commonly used modules in full (Data.Foldable, Data.Applicative, and
so on); though only those that play nicely with each other, so that
XMonad.Prelude can be imported unqualified without any problems.
This prevents things like `Prelude.(.)` and `Control.Category.(.)`
fighting with each other.
b) Helper functions that don't necessarily fit in any other module;
e.g., the often used abbreviation `fi = fromIntegral`.
