Fix maintainer-check failure; sync upstream files.

[Ralf Wildenhues]

FWIW, I've synced config.guess, config.sub, and texinfo.tex from
upstream, and fixed a maintainer-check failure as below, both patches
for maint.

Cheers,
Ralf

    Fix maintainer-check failure.
    
    * tests/cond5.test: Quote sleep argument, this isn't about
    time stamp differences.

diff --git a/tests/cond5.test b/tests/cond5.test
index 88e2e42..50101a6 100755
--- a/tests/cond5.test
+++ b/tests/cond5.test
@@ -48,15 +48,16 @@ $ACLOCAL
 $AUTOMAKE 2>stderr &
 pid=$!
 
-# MSYS bash seems to have a bug in kill, so don't try to kill too soon.
-sleep 2
+# MSYS bash seems to have a bug in kill, so don't try to kill too soon;
+# and avoid maintainer-check test.
+sleep '2'
 
 # Make at most 30 tries, one every 10 seconds (= 300 seconds = 5 min).
 try=1
 while test $try -le 30; do
   if kill -0 $pid; then
     : process $pid is still alive, wait and retry
-    sleep 10
+    sleep '10'
     try=`expr $try + 1`
   else
     cat stderr >&2