gnulib: update to latest and adapt printf-quote.sh test

* .gitignore: Add /lib/limits.h.
* tests/misc/printf-quote.sh: Reflect that a single quote is now
rendered as "'", rather than as ''\'''.

.gitignore

@@ -68,6 +68,7 @@
 /lib/inttypes.h
 /lib/langinfo.h
 /lib/libcoreutils.a
+/lib/limits.h
 /lib/link-warning.h
 /lib/locale.h
 /lib/math.h

tests/misc/printf-quote.sh

@@ -25,7 +25,7 @@ prog='env printf'
 $prog '%q\n' '' "'" a 'a b' '~a' 'a~' "$($prog %b 'a\r')" > out
 cat <<\EOF > exp || framework_failure_
 ''
-''\'''
+"'"
 a
 'a b'
 '~a'