m4: grab newer upstream m4 (for code-coverage)

Grab some newer version of the autotools m4 archive, as we need those to
setup code-coverage.

Remove some unneeded ones.

m4/ax_am_macros_static.m4

@@ -0,0 +1,38 @@
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_am_macros_static.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_AM_MACROS_STATIC
+#
+# DESCRIPTION
+#
+#   Adds support for macros that create Automake rules. You must manually
+#   add the following line
+#
+#     include $(top_srcdir)/aminclude_static.am
+#
+#   to your Makefile.am files.
+#
+# LICENSE
+#
+#   Copyright (c) 2009 Tom Howard <tomhoward@users.sf.net>
+#   Copyright (c) 2009 Allan Caffee <allan.caffee@gmail.com>
+#
+#   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 11
+
+AC_DEFUN([AMINCLUDE_STATIC],[aminclude_static.am])
+
+AC_DEFUN([AX_AM_MACROS_STATIC],
+[
+AX_AC_PRINT_TO_FILE(AMINCLUDE_STATIC,[
+# ]AMINCLUDE_STATIC[ generated automatically by Autoconf
+# from AX_AM_MACROS_STATIC on ]m4_esyscmd([LC_ALL=C date])[
+])
+])