Switch from SIGHUP to SIGTERM

to: @nolman 

SIGHUP seems to me to be the wrong signal to use in this situation. I tested it on a ruby process and it does work to exit it but it would be totally acceptable for a Ruby process to catch SIGHUP and reload a config or something.

AFAIK SIGTERM followed by SIGKILL is more suitable.

Nolan, do you remember your reasoning for picking SIGHUP?