Add tr to common programs

[Eric Blake]

A bug report on the autoconf list recently reported that autoconf has been
producing configure files for several years now with a dependence on
tr[1], even though tr is not listed in the set of safe programs[2].  Since
there have been no bug reports about an inability to configure packages
because of the use of tr, I propose adding it to the set of approved
programs (note that autoconf already lists some portability issues to be
aware of when using tr[3]).

[1] http://lists.gnu.org/archive/html/autoconf/2008-10/msg00124.html
[2]
http://www.gnu.org/software/automake/manual/standards.html#Utilities-in-Makefiles
[3]
http://www.gnu.org/software/autoconf/manual/autoconf.html#Limitations-of-Usual-Tools,
under tr

2008-11-04  Eric Blake  <address@hidden>

        * doc/make-stds.texi (Utilities in Makefiles): Add tr.

diff --git a/doc/make-stds.texi b/doc/make-stds.texi
index bd4df50..98e5e86 100644
--- a/doc/make-stds.texi
+++ b/doc/make-stds.texi
@@ -161,7 +161,7 @@ Utilities in Makefiles

 @example
 awk cat cmp cp diff echo egrep expr false grep install-info
-ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch true
+ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch tr true
 @end example

 Compression programs such as @code{gzip} can be used in the

-- 
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden