Issue 241 withdrew seven consumers in one pass on one misread file; its fix
refuses a file it cannot read, and a file read whole that names nobody
still withdraws everybody. A pass that would withdraw more than one
consumer at once, or more than half of those it holds, now withdraws
nothing: each consumer it kept is announced provisioner.failing with the
class withdrawal-braked, so the controller raises it as a condition and
the operator is told, and one is let go each hour while the mesh goes on
not asking for them. A consumer asked for again is kept and said recovered.
Postgres and keycloak carry the harness identically.
jochen