XMonad.Prompt: Allow Pointer Events
XMonad.Prompt: Allow Pointer Events

If this is not done, trying to select another window with the mouse when
the prompt is up, the X server executes a pointer/keyboard grab until
`allowEvents' is called; which it never is and so both remain frozen
indefinitely.

C.f.:
  - xmonad/xmonad/issues/116
  - xmonad/xmonad-contrib/issues/445

xmonad/xmonad-contrib,xmonad/xmonad-contrib