chg: do not write pidfile Current pidfile logic will only keep the pid of the newest server, which is not very useful if we want to kill all servers, and will become outdated if the server auto exits after being idle for too long. Besides, the server-side pidfile writing logic runs before chgserver gets confighash so it's not trivial to append confighash to pidfile basename like we did for socket file. This patch removes --pidfile from the command starting chgserver and switches to an alternative way (unlink socket file) to stop the server.

chg: remove manual reload logic chgserver now validates and reloads configs automatically. Manually reloading is no longer necessary. Besides, we are deprecating pid files since the server will periodically check its ownership of the socket file and exit if it does not own the socket file any longer, which works more reliable than a pid file. This patch removes the SIGHUP reload logic from both chg server and client.

chg: use --daemon-postexec chdir:/ instead of --cwd / The chgserver is designed to load repo config from current directory. "--cwd /" will prevent chgserver from loading repo config and generate a wrong confighash, which will result in a redirect loop. This patch removes "--cwd /" and uses "--daemon-postexec chdir:/" instead.