* fhandler_disk_file.cc (fhandler_disk_file::facl): Ditto in noacl case.
* sec_acl.cc (getacl): Compute useful fake CLASS_OBJ and DEF_CLASS_OBJ
permission bits based on how these values are generated on Linux.
Add commants to explain what the code is doing.
* security.cc (get_attribute_from_acl): Compute group permission based
on the actual primary group permissions and all secondary user and group
ACCESS_ALLOWED_ACEs to emulate Linux' behaviour more closely.
(check_access): Fix typos im comment.
* include/cygwin/acl.h (MIN_ACL_ENTRIES): Redefine as 3.