retry failed backups after ten minutes
notifications can be closed
remove obsolete file
use pry-debugger
refactor duplication code
move UpToDateness into a new home
Orchestrator: propagate primary timestamp also initially
move responsibility out of DSL executor into factory
Factory: refactor and make almost every method private
separate general destination option from specific ones, handle max_space
a central handle for naming a primaries' backups
update preliminary config example
fixed copyright header
duplication target base class; split general options from duplication target specific ones
better destination naming
better BackupName fallback
bugfix in udev2 service: actually register when disk is no longer seen