Fixed notifications following outdated pomo timers if the timer was ever
paused or restarted. Will now limit the pomo timer to a single 'running'
instance containing the notification function.
Using [jsspencer/pomo](https://github.com/jsspencer/pomo) as the timer
of choice. It is simple, it works well, and it uses a very elegant way
of tracking the time.
I can think about implementing my own version later, but this will
handily suffice for now.
Having a general script folder makes little sense if the scripts are
targeted to specific applications. This commit moved every script that
solely, or mainly (like ueberzug), targets a single application into
that respective stow module.
