Get unix_sock_group & config_sys as an option

- unix_sock_group: libvirt 3.x from UCA repo by default uses
  "libvirt" group for socket ownership, so get the name
  of the group from pillar if given.
- config_sys: handle sysconfig file location
  defined in parameters.

Change-Id: I06dd3707efc191a81af1cf60d8dbeef4e9ea5964
4 files changed