Before, we were activating Let's Encrypt after all the directives were executed. This means their setup functions had access to potentially erroneous information about the server's TLS setup, since the letsencrypt package makes changes to the port, etc. Now, we execute all directives up to and including tls, then activate letsencrypt, then finish with the rest of the directives. It's a bit ugly, but I do think it is more correct. It also fixes some bugs, for example: a host that only has a catch-all redirect.
The file path of the originally-loaded Caddyfile must be piped to the forked process; previously it was using stdin after the first fork, which wouldn't load the newest Caddyfile from disk, which is the point of SIGUSR1.
OCSP status is checked at a regular interval, and if the OCSP status changes for any of the certificates, the change callback is executed (restarts the server, updating the OCSP staple).
Merged config and app packages into one called caddy. Abstracted away caddy startup functionality making it easier to embed Caddy in any Go application and use it as a library. Graceful restart (should) now ensure child starts properly. Now piping a gob bundle to child process so that the child can match up inherited listeners to server address. Much cleanup still to do.