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`.
Change the border resize rectangles to be narrower and only extend
inside the window not outside. Most window managers just seem to use
the border decoration area for starting resizes which is often just 1 pixel
wide but as a compromise the width is now 2 pixels (before it was 10!).
The rectangles are now placed symmetrically within the border and window.
This seems to work ok with PositionStoreFloat for the Bluetile config.
