churn: use the non-deprecated template option in the examples

sslutil: reference fingerprints config option properly (issue5559) The config option is "host:fingerprints" not "host.fingerprints". This warning message is bad and misleads users.

largefiles: make sure debugstate command is populated before wrapping Copied the hack from 869d660b8669, which seemed the simplest workaround. Perhaps debugcommands.py should have its own commands table.