Bump version (and xmonad dependency) to 0.12
Bump version (and xmonad dependency) to 0.12


This makes a breakage due to missing patches in core a bit more obvious.
Previously you would have a build failure regarding some missing identifiers
(def re-exported by XMonad from Data.Default), while after applying this patch
it will be clear that xmonad-core needs to be updated.

0/xmonad-contrib,0/xmonad-contrib,ohlus/xmonad-contrib,ohlus/xmonad-contrib,mathstuf/xmonad-contrib,0/xmonad-contrib,CaptainPatate/xmonad-contrib,f1u77y/xmonad-contrib,CaptainPatate/xmonad-contrib,xmonad/xmonad-contrib,f1u77y/xmonad-contrib,mathstuf/xmonad-contrib,mathstuf/xmonad-contrib,xmonad/xmonad-contrib,ohlus/xmonad-contrib,CaptainPatate/xmonad-contrib,pjones/xmonad-test