Add mes and mescc-tools-extra

mescc-tools-extra contains two important tools:
- cp
- chmod

mes first builds itself from a mes 0.21 seed as used by guix, and then
builds a mes 0.22 and then mes 0.22 using that created mes 0.22.

It does /not/ use bootstrap.sh as we don't have a proper shell at this
point, it has been manually adapted for kaem.

sysa/mes-0.22/doc/images/README

@@ -0,0 +1,13 @@
+                                                              -*- org -*-
+#+TITLE: GNU Mes images
+
+Copyright © 2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+
+  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.
+
+gcc-mesboot-graph.dot
+This graph is generated from Guix wip-bootstrap, doing:
+~/src/guix/core-updates/pre-inst-env guix graph --type=bag -e '(@@ (gnu packages commencement) gcc-mesboot)' > doc/images/gcc-mesboot-graph.dot
+dot -T png doc/images/gcc-mesboot-graph.dot > doc/images/gcc-mesboot-graph.png