Remove the notion of "sys*"

- This idea originates from very early in the project and was, at the
  time, a very easy way to categorise things.
- Now, it doesn't really make much sense - it is fairly arbitary, often
  occuring when there is a change in kernel, but not from builder-hex0
  to fiwix, and sysb is in reality completely unnecessary.
- In short, the sys* stuff is a bit of a mess that makes the project
  more difficult to understand.
- This puts everything down into one folder and has a manifest file that
  is used to generate the build scripts on the fly rather than using
  coded scripts.
- This is created in the "seed" stage.

stage0-posix -- (calls) --> seed -- (generates) --> main steps

Alongside this change there are a variety of other smaller fixups to the
general structure of the live-bootstrap rootfs.

- Creating a rootfs has become much simpler and is defined as code in
  go.sh. The new structure, for an about-to-be booted system, is

/
-- /steps (direct copy of steps/)
-- /distfiles (direct copy of distfiles/)
-- all files from seed/*
-- all files from seed/stage0-posix/*

- There is no longer such a thing as /usr/include/musl, this didn't
  really make any sense, as musl is the final libc used. Rather, to
  separate musl and mes, we have /usr/include/mes, which is much easier
  to work with.
- This also makes mes easier to blow away later.
- A few things that weren't properly in packages have been changed;
  checksum-transcriber, simple-patch, kexec-fiwix have all been given
  fully qualified package names.
- Highly breaking change, scripts now exist in their package directory
  but NOT WITH THE packagename.sh. Rather, they use pass1.sh, pass2.sh,
  etc. This avoids manual definition of passes.
  - Ditto with patches; default directory is patches, but then any patch
    series specific to a pass are named patches-passX.

steps/bash-2.05b/patches/missing-defines.patch

@@ -0,0 +1,29 @@
+SPDX-FileCopyrightText: 2021 fosslinux <fosslinux@aussies.space>
+
+SPDX-License-Identifier: GPL-2.0-or-later
+
+We don't actually want any of these things, which should really be hidden
+behind the ifdefs given here to disable them when they are not being
+used (as we do).
+
+--- execute_cmd.c	2021-01-15 09:38:55.730307635 +1100
++++ execute_cmd.c	2021-01-15 09:43:41.046896754 +1100
+@@ -286,12 +286,18 @@
+     {
+       if (currently_executing_command->type == cm_simple)
+ 	return currently_executing_command->value.Simple->line;
++#ifdef COND_COMMAND
+       else if (currently_executing_command->type == cm_cond)
+ 	return currently_executing_command->value.Cond->line;
++#endif
++#ifdef DPAREN_ARITHMETIC
+       else if (currently_executing_command->type == cm_arith)
+ 	return currently_executing_command->value.Arith->line;
++#endif
++#ifdef ARITH_FOR_COMMAND
+       else if (currently_executing_command->type == cm_arith_for)
+ 	return currently_executing_command->value.ArithFor->line;
++#endif
+       else
+ 	return line_number;
+     }