This is a bit of a blunt tool -- might be better to do a temporary boost
when recording progress, based on the amount of time spent *making* that
progress like in manage_shard_ranges -- but I definitely *don't* want to
get through a 4 hour cleave and then *fail to record that*.
Default to 60s, which is more than twice the default timeout, but give
operators the option to set it as they like.
Change-Id: If518d503b0995051f7dafcbb73ac3c9889fe450f
33ee15b8aa