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not very useful if we want to kill all servers, and will become outdated if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.
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)