[arch-proaudio] limits.conf for jack

[Ralf Mardorf]

I prefer to stay with the audio group for rtprio and memlock,
since migrating to a new group wouldn't be an advantage for me and only
would cause work, e.g. rewriting scripts that check if a user is in the
audio group or fixing scripts that chown' a directory or file for
realtime users. Anything useful for those using pulseaudio, skype or
similar crap is not related to the needs of realtime audio
workstation users. It's a PITA that this rubbish (to care about
pulseaudio and skype in the context of a realtime audio
workstation) gains more and more ground, while there is lean manpower
for the Linux pro-audio domain. A good reason to migrate to another OS
for pro-audio, if Linux pro-audio development attracts less attention,
than bonding counter-productive software. I had doubts to completely
migrate to a restricted OS for pro-audio, even while I already use a
combination of Linux and Pear, but I get more and more convinced that
this soon or later becomes the lesser evil.