* libmisc/pwdcheck.c: Do not include <pwd.h>. Include <shadow.h>

and "pwauth.h" only when compiled without PAM support.
* src/chfn.c, src/chsh.c: Do not include <shadow.h>
* lib/commonio.c: Do not include <shadow.h>. Do not include
  <pwd.h>. Include "nscd.h" instead of <nscd.h>.
* configure.in: Do not check if shadow.h exist, but make sure it
  exists.
* libmisc/pwdcheck.c, src/chfn.c, src/chsh.c, lib/defines.h,
  lib/shadowmem.c, lib/shadowio.c, lib/commonio.c:
  HAVE_SHADOW_H is no more needed (shadow.h should always exist).

configure.in

@@ -31,9 +31,12 @@ AC_HEADER_SYS_WAIT
 
 AC_CHECK_HEADERS(errno.h fcntl.h limits.h unistd.h sys/time.h utmp.h \
 	utmpx.h termios.h termio.h sgtty.h sys/ioctl.h syslog.h paths.h \
-	utime.h ulimit.h sys/resource.h gshadow.h shadow.h lastlog.h \
+	utime.h ulimit.h sys/resource.h gshadow.h lastlog.h \
 	locale.h rpc/key_prot.h netdb.h)
 
+dnl shadow now uses the libc's shadow implementation
+AC_CHECK_HEADER([shadow.h],,[AC_MSG_ERROR([You need a libc with shadow.h])])
+
 AC_CHECK_FUNCS(l64a fchmod fchown fsync getgroups gethostname getspnam \
 	gettimeofday getusershell getutent initgroups lchown lckpwdf lstat \
 	memcpy memset setgroups sigaction strchr updwtmp updwtmpx innetgr \