* libmisc/console.c, libmisc/ulimit.c, lib/sgetgrent.c,

* libmisc/console.c, libmisc/ulimit.c, lib/sgetgrent.c,
  lib/sgetpwent.c: Include "prototypes.h" to make
  sure the exported prototypes are the ones used for the definition
  of functions.
* lib/prototypes.h: Added prototypes for __gr_del_entry(),
  __gr_get_db(), __gr_get_head(), __gr_set_changed(), __gr_dup(),
  __pw_del_entry(), __pw_get_db(), __pw_get_head(), __pw_dup(),
  sgetgrent(), sgetpwent(), __sgr_del_entry(), __sgr_dup(),
  __sgr_get_head(), __sgr_set_changed(), __spw_get_head(),
  __spw_del_entry(), __spw_dup().
* lib/prototypes.h: Removed prototype for is_listed().
* lib/prototypes.h: Added name of the check_su_auth()'s parameters.
* lib/groupio.h: Removed prototypes for __gr_dup() and
  __gr_set_changed().
* lib/sgroupio.c: Removed prototypes for putsgent(), sgetsgent(),
  and __gr_get_db().
* lib/sgroupio.h: Removed prototypes for __sgr_dup() and
  __sgr_set_changed().
* lib/shadowio.c: Removed prototype for __pw_get_db().
* lib/pwio.c: Removed prototype for sgetpwent() and putpwent().
* lib/shadowio.h: Removed prototypes for __spw_dup() and
  __spw_set_changed().
* lib/pwio.h: Removed prototypes for __pw_dup() and
  __pw_set_changed().
* lib/commonio.h: Add protection against multiple inclusions.
* lib/prototypes.h: Include commonio.h (needed for the
  __xx_del_entry() functions).