Dev: Shell: work around lrmd/lrmadmin blocking when not run as root or hacluster

This needs to be fixed in lrmd (probably) or the IPC code. For
now, we simply use the OS interface for unprivileged users.
(transplanted from 63f0733f673557dbc0243ad2337acfee8fa88b18)

Mercurial revision: 9dd6918bb6fcae0d02387b9646315d7b09f37451