Use strtonum() instead of strtoul() when parsing uid/gid so we get

Use strtonum() instead of strtoul() when parsing uid/gid so we get
consistent handling of negative ids on 32bit/64bit systems.
The only negative uid/gid allowed is -1 which is special-cased
so it can be preserved when writing the new master.passwd file
instead of being written as an unsigned number.  OK deraadt@