WIP: software/erp5: Add rlimit_nofile (?) option (2)

Hello,

due to the reasons stated in https://lab.nexedi.com/nexedi/slapos/merge_requests/1451#note_193296 merge request https://lab.nexedi.com/nexedi/slapos/merge_requests/1451 was dropped by force pushing to master branch.

So I open this up again. We need to find a consensuses regarding the name of the option which sets the soft limit of open file descriptors to its hard limit. Once we find this consensuses I can push a fixup commit to ERP5, then adjust the name here, adjust the commit messages according to https://lab.nexedi.com/nexedi/slapos/merge_requests/1451#note_193296 and finally hopefully merge again.

In https://lab.nexedi.com/nexedi/slapos/merge_requests/1451#note_193297 @jm suggested rlimit-nofile++ or

something more Nexediish

I was thinking of a verbose --max-soft-fds-limit. Are there any other concrete ideas or opinions?

Best, Levin

++ I'd go for - instead of _, because the other zopewsgi options use - and @jerome suggested using - as a convention in SlapOS parameters instead of _. So we could even use the same style for both ERP5 and SlapOS, which makes it easier to memorize.

/cc @vpelletier