find-principals
- adds generic find-principals tests (this command had none before)
- tests certs with a timeboxed validity both with and without a
restriced lifetime for the CA
- test for a revoked CA cert
by Fabian Stelzer
OpenBSD-Regress-ID: 9704b2c6df5b8ccfbdf2c06c5431f5f8cad280c9
check-novalidate signature test mode and signing keys in ssh-agent.
From Sebastian Kinne (slightly tweaked)
OpenBSD-Regress-ID: b39566f5cec70140674658cdcedf38752a52e2e2