* security.h: New define `NO_SID'. Remove declarations of functions
moved to methods into class cygsid.
(class cygsid): Declare new methods `getfromstr', `get_sid',
`getfrompw', `getfromgr', `get_rid', `get_uid', `get_gid', `string'
and new constructors and operators =, == and !=.
Declare new global cygsids `well_known_XXX_sid' substituting the
corresponding `get_XXX_sid' functions. Remove declarations of
these functions.
* sec_helper.cc (well_known_admin_sid): New global variable.
(well_known_system_sid): Ditto
(well_known_creator_owner_sid): Ditto
(well_known_world_sid): Ditto
(cygsid::string): New method, substituting `convert_sid_to_string_sid'.
(cygsid::get_sid): New method, substituting `get_sid'.
(cygsid::getfromstr): New method, substituting
`convert_string_sid_to_sid'.
(cygsid::getfrompw): New method, substituting `get_pw_sid'.
(cygsid::getfromgr): New method, substituting `get_gr_sid'.
(cygsid::get_id): New method, substituting `get_id_from_sid'.
(get_admin_sid): Eliminated.
(get_system_sid): Ditto.
(get_creator_owner_sid): Ditto.
(get_world_sid): Ditto.
* grp.cc: Use new cygsid methods and well known sids throughout.
* registry.cc: Ditto.
* sec_acl.cc: Ditto.
* security.cc: Ditto.
* shared.cc: Ditto.
* syscalls.cc (seteuid): Ditto. Eliminate redundant conditional.
* uinfo.cc (internal_getlogin): Ditto.
* spawn.cc (spawn_guts) Revert previous patch.
2b0a111fcf