declare builtin changes to reject -i when used with -n; readline changes to make control characters visible in search strings; readline signal handling changes to avoid data corruption and UAF; documentation updates for more consistent quoting

tests/comsub23.sub

@@ -81,7 +81,7 @@ echo and ${word-${ echo work here; }}
 unset x
 
 set -- 'a[${ break;}]'
-declare -in x
+declare -n x
 
 for x do :; done
 echo after for