* bootstrap: Import improvements from latest gnulib.

lib/.cvsignore

@@ -21,12 +21,14 @@ dirname.c
 dirname.h
 dup-safer.c
 dup2.c
+errno.h
 errno.in.h
 error.c
 error.h
 exitfail.c
 exitfail.h
 fcntl.c
+fcntl.h
 fcntl.in.h
 fd-safer.c
 fopen-safer.c
@@ -70,6 +72,7 @@ stamp-h1
 stdbool.h
 stdbool.in.h
 stdbool_.h
+stddef.h
 stddef.in.h
 stdint.h
 stdint.in.h
@@ -77,6 +80,7 @@ stdint_.h
 stdio--.h
 stdio-safer.h
 stdio-write.c
+stdio.h
 stdio.in.h
 stdlib.h
 stdlib.in.h