update section about who uses autotest

[Bruno Haible]

Hi,

The doc says that "Bison, Free Recode, Free Wdiff, GNU Tar" uses autotest.
This needs an update:
  * Free Recode no longer uses autotest, see
    https://github.com/pinard/Recode/tree/master/tests
    (note the change entry "Use pytest instead of Autotest").
  * Free Wdiff is now GNU wdiff again, see
    http://ftp.gnu.org/gnu/wdiff/

Here's a proposed patch.


2016-12-14  Bruno Haible  <address@hidden>

        * doc/autoconf.texi (Using Autotest): Stop mentioning Free Recode.
        Free Wdiff is now GNU Wdiff again.

--- doc/autoconf.texi.orig      2016-11-07 17:28:11.000000000 +0100
+++ doc/autoconf.texi   2016-12-14 18:41:18.000000000 +0100
@@ -24893,7 +24893,7 @@
 Autoconf itself has been using Autotest for years, and we do attest that
 it has considerably improved the strength of the test suite and the
 quality of bug reports.  Other projects are known to use some generation
-of Autotest, such as Bison, Free Recode, Free Wdiff, GNU Tar, each of
+of Autotest, such as Bison, GNU Wdiff, GNU Tar, each of
 them with different needs, and this usage has validated Autotest as a general
 testing framework.