We had to hack some special support into the server and caddy packages for this. There are some middlewares which should only execute commands when the original parent process first starts up. For example, someone using the startup directive to start a backend service would not expect the command to be executed every time the config was reloaded or changed - only once when they first started the original caddy process.
This commit adds FirstStartup to the virtualhost config
Addresses which fail to resolve are handled more gracefully in the two most common cases: the hostname doesn't resolve or the port is unknown (like "http" on a system that doesn't support that port name). If the hostname doesn't resolve, the host is served on the listener at host 0.0.0.0. If the port is unknown, we attempt to rewrite it as a number manually and try again.
