This fixes several issues related to parsing of parent PIDs:
* A process with lines or spaces or parentheses in its process name
would confuse the code in X.A.SpawnOn and possibly lead to a
`Prelude.read: no parse` exception.
* `X.H.WindowSwallowing.isChildOf` looked for the parent PID anywhere in
the output of pstree, so single-digit parent PIDs would be considered
as parents of any process with that digit anywhere in its chain of
parent PIDs. (Note that apps in PID namespaces like in Flatpak often
have single-digit PIDs.)
* `pstree` is no longer required in `$PATH`.
Fixes: https://github.com/xmonad/xmonad-contrib/issues/726
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`.
