* lib/shadowmem.c: Only copy the required fields of the struct
spwd. (start with the primitive types)
* lib/shadowmem.c: Avoid memzero() on a possibly NULL pointer.
* lib/groupmem.c: Only copy the required fields of the struct
group. (start with the primitive types)
* lib/groupmem.c: Avoid memzero() on a possibly NULL pointer.
* lib/groupmem.c: Free gr_mem in addition to its elements.
* lib/sgroupio.c: The struct sgrp has no primitive types to be
copied initially.
* lib/sgroupio.c: Avoid memzero() on a possibly NULL pointer.
* lib/sgroupio.c: Free sg_mem and sg_add in addition to their
elements.
* lib/pwmem.c: Only copy the required fields of the struct
passwd. (start with the primitive types)