Grants first could hold back the very declaration that lets the controller
issue them. The holder now goes first, then buckets and memberships, then
the rest; a membership that fails holds back only its own machine, and an
announcement whose send stopped at its grants is asked again. Whether the
holder must go first is read from a digest of the user list it was last
sent, not its whole declaration. Migration renumbered to 0058.
A module's new state reached every machine before the permissions to use
it, which came only with a later push. Memberships and buckets now go
before declarations, the machine holding mesh-broker goes first when its
user list must change, and a grant that fails sends nothing and is an
error so the rollout is retried.