Support daemon and pidfile.

[hungrybirder]

Hello Corvus Main Developers.

I have implemented daemon feature in my branch called deamon.

Please check.

If it's OK, Please merge.

Thank you. Best wishes!

[doyoubi]

Hi, thanks for this feature. But now we have some good process managing tools like supervisord and systemd. I think we don't need to build it ourselves.

[hungrybirder]

Someone can also use supervisord or systemd by adding this feature, no conflicts. In my workspace, I don't wanna use supervisord ro systemd. I write some scripts like corvus_install, corvus_start, corvus_stop, etc.. for managing multi corvus instances. But it's fine~,I respect your choice. I'll keep watching the amazing corvus project. Thank you. ^_^

[CLAassistant]

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