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/mes/module/srfi/srfi-9/gnu-vector.mes

@@ -0,0 +1,37 @@
+;;; -*-scheme-*-
+
+;;; GNU Mes --- Maxwell Equations of Software
+;;; Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+;;;
+;;; This file is part of GNU Mes.
+;;;
+;;; GNU Mes is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Mes is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; srfi-9.mes - GNU immutable records.
+
+(define-macro (define-immutable-record-type type constructor+params predicate . fields)
+  `(define-record-type ,type ,constructor+params ,predicate ,@(map (lambda (f) (list-head f 2)) fields)))
+
+(define-macro (set-field o getters value)
+  `(let ((getter ,(car getters)))
+     (let ((type (record-type ,o))
+           (set (getter ,o #t)))
+       (define (field->value field)
+         (if (eq? set field) ,value
+             ((record-getter type field) ,o)))
+       (let* ((fields (record-fields type))
+              (values (map field->value fields)))
+         (apply (record-constructor type fields) values)))))