Autoconf fixes (#1266)

* Remove typoed and unused check for a curl header.

* Add perl version check.

* Handle versions of tar that don't understand how to decompress tarballs.

* Disable checking for -fstack-protector on AIX.

* Disable slaves on all Windows platforms and IPv6 on Cygwin.

* Rebuild configure and add hints/aix.txt

aclocal.m4

@@ -3278,3 +3278,73 @@ AC_DEFUN([AX_ADD_FORTIFY_SOURCE],[
             AC_MSG_RESULT([no])
     ])
 ])
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_prog_perl_version.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PROG_PERL_VERSION([VERSION],[ACTION-IF-TRUE],[ACTION-IF-FALSE])
+#
+# DESCRIPTION
+#
+#   Makes sure that perl supports the version indicated. If true the shell
+#   commands in ACTION-IF-TRUE are executed. If not the shell commands in
+#   ACTION-IF-FALSE are run. Note if $PERL is not set (for example by
+#   running AC_CHECK_PROG or AC_PATH_PROG) the macro will fail.
+#
+#   Example:
+#
+#     AC_PATH_PROG([PERL],[perl])
+#     AX_PROG_PERL_VERSION([5.8.0],[ ... ],[ ... ])
+#
+#   This will check to make sure that the perl you have supports at least
+#   version 5.8.0.
+#
+#   NOTE: This macro uses the $PERL variable to perform the check.
+#   AX_WITH_PERL can be used to set that variable prior to running this
+#   macro. The $PERL_VERSION variable will be valorized with the detected
+#   version.
+#
+# LICENSE
+#
+#   Copyright (c) 2009 Francesco Salvestrini <salvestrini@users.sourceforge.net>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 13
+
+AC_DEFUN([AX_PROG_PERL_VERSION],[
+    AC_REQUIRE([AC_PROG_SED])
+    AC_REQUIRE([AC_PROG_GREP])
+
+    AS_IF([test -n "$PERL"],[
+        ax_perl_version="$1"
+
+        AC_MSG_CHECKING([for perl version])
+        changequote(<<,>>)
+        perl_version=`$PERL --version 2>&1 \
+          | $SED -n -e '/This is perl/b inspect
+b
+: inspect
+s/.* (\{0,1\}v\([0-9]*\.[0-9]*\.[0-9]*\))\{0,1\} .*/\1/;p'`
+        changequote([,])
+        AC_MSG_RESULT($perl_version)
+
+	AC_SUBST([PERL_VERSION],[$perl_version])
+
+        AX_COMPARE_VERSION([$ax_perl_version],[le],[$perl_version],[
+	    :
+            $2
+        ],[
+	    :
+            $3
+        ])
+    ],[
+        AC_MSG_WARN([could not find the perl interpreter])
+        $3
+    ])
+])