Build system: add script to generate autotools files

Add a bootstrap script to generate the autotools files.
Those files are no longer needed after that commit and
can be removed from the source tree.

bootstrap.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+mkdir -p aux_scripts m4
+libtoolize -c -i
+aclocal -I m4 --install
+autoheader
+automake -a -c
+autoconf
+