(PUP-266) Ensure ADSI Group SIDs may be looked up

 - Previously, calling Puppet::Util::ADSI::Group.exists? for a
   well-known group SID would return false, because the WinNT:// style
   URI used to find the group would not examine / lookup the SID, but
   would instead create a broken Uri that the underlying OS could not
   understand
 - Now, the given group name is checked to see if it's a SID before the
   Uri is constructed, and a SID style Uri is created where appropriate
(18342) Puppet manages group and owner on config

 - Previously, Puppet would ignore the configuration in defaults.rb for
   setting a group / owner on a given file or directory -- even when
   the Windows machine was running with administrative permissions
 - Since Windows now has the capability of properly setting a group
   and owner, allow Windows to manage these permissions when
   appropriate
 - The existing Puppet::Settings::FileSettings::Service class
   depends on looking up the appropriate default service accounts
   for use in a number of locations. To fall in line with this usage
   pattern, "Administrators" is set as the default owner and
   the "Service" group S-1-5-6 is set as the default group.  This
   special OS managed group includes all accounts with the logon
   as a service token privilege.