Soft stop of queue worker - Support for pcntl signals (For ex. stopping from supervisor or by SIGTERM)

[xYundy]

Hey! For now when you use supervisor or if you wanna try "soft stop" the queue worker by SIGTERM it will be killed/exited immediately.

I think app should support SIGTERM (or maybe others) signal and stop the process after finish currently running task.

It will be helpful for ex when you release new version of application and you want to stop, upgrade and restart queue workers without loosing or interrupting any work.

Helpful Links

https://www.php.net/manual/en/function.pcntl-signal.php
http://www.hackingwithphp.com/16/1/1/taking-control-of-php