- doc - Add WHAT IS DANE? section
- Add _ to set of DNS name chars that don't require idn2
- rollover - Divert certbot stdout to stderr to aid output adapters
- Prevent premature rollover (refuse if tlsa-check would fail)
- Terminate danectl when `idna` in subprocess requires idn2 but fails to find it
- Makefile - Add make help (default)