rysnc:
. Fix numericids option (Redmine#3691).
. Mangle $rsync_options just afterwards (Redmine#3702).
+ . Fix metadata rotation.
+ . Allow disabling rotation or setting 2 days as minimum for backup
+ increments in rsync short format (Redmine#2107).
+ . Use fatal instead of custom "exit 1" (Redmine#3721).
+ . Abort on rsync error (Redmine#3692).
dup:
. Make the .dup generated by ninjahelper more consistent with
example.dup.