* Add support for Darwin Directory Service groups
This allows users to verify groups added by Chef on OS X.
The current method that `UnixGroup` uses is to check the contents of
`/etc/group`, but OS X adds groups to Directory Service and not
`/etc/group`. This modifies the `group` resource on Darwin to use
`dscacheutil` to get group info.
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>
* Clean up `select_group_manager`
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>
* Clean up DarwinGroup `groups` method
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>