Merge branch 'ds/scalar-no-maintenance'

Two "scalar" subcommands that adds a repository that hasn't been under "scalar"'s control are taught an option not to enable the scheduled maintenance on it. * ds/scalar-no-maintenance: scalar reconfigure: improve --maintenance docs scalar reconfigure: add --maintenance=<mode> option scalar clone: add --no-maintenance option scalar register: add --no-maintenance option scalar: customize register_dir()'s behavior