Patch by Kazuhiro Fujieda <fujieda@jaist.ac.jp>:

Patch by Kazuhiro Fujieda  <fujieda@jaist.ac.jp>:
        * mkgroup.c (enum_groups): Use RID + offset specified an additional
        argument as ID.
        (usage): Add description of -o option.
        (longopts, opts): Add specifications of -o/--id-offset option.
        (main): Add -o option. Invoke enum_groups with specified offset.
        * mkpasswd.c (enum_users): Just like mkgroup.c.
        (usage, longopts, opts): Ditto.
        (main): Add -o option. Invoke enum_users with specified offset
        only against domain accounts.