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/coreutils-5.0/patches/uniq-fopen.patch

@@ -0,0 +1,68 @@
+SPDX-FileCopyrightText: 2005 Paul Eggert <eggert@cs.ucla.edu>
+SPDX-FileCopyrightText: 2023 Emily Trau <emily@downunderctf.com>
+
+SPDX-License-Identifier: GPL-2.0-or-later
+
+uniq: don't assume fopen cannot return stdin or stdout.
+Backport of https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=786ebb2ceca72f69aa2de701671fb41f53cb1489
+
+--- src/uniq.c
++++ src/uniq.c
+@@ -30,6 +30,7 @@
+ #include "error.h"
+ #include "hard-locale.h"
+ #include "posixver.h"
++#include "stdio-safer.h"
+ #include "xmemcoll.h"
+ #include "xstrtol.h"
+ #include "memcasecmp.h"
+@@ -267,20 +268,26 @@ check_file (const char *infile, const char *outfile)
+   FILE *ostream;
+   struct linebuffer lb1, lb2;
+   struct linebuffer *thisline, *prevline;
++  bool is_stdin = STREQ (infile, "-");
++  bool is_stdout = STREQ (outfile, "-");
+ 
+-  if (STREQ (infile, "-"))
++  if (is_stdin)
+     istream = stdin;
+   else
+-    istream = fopen (infile, "r");
+-  if (istream == NULL)
+-    error (EXIT_FAILURE, errno, "%s", infile);
++    {
++      istream = fopen_safer (infile, "r");
++      if (! istream)
++        error (EXIT_FAILURE, errno, "%s", infile);
++    }
+ 
+-  if (STREQ (outfile, "-"))
++  if (is_stdout)
+     ostream = stdout;
+   else
+-    ostream = fopen (outfile, "w");
+-  if (ostream == NULL)
+-    error (EXIT_FAILURE, errno, "%s", outfile);
++    {
++      ostream = fopen_safer (outfile, "w");
++      if (! ostream)
++        error (EXIT_FAILURE, errno, "%s", outfile);
++    }
+ 
+   thisline = &lb1;
+   prevline = &lb2;
+@@ -377,12 +384,12 @@ check_file (const char *infile, const char *outfile)
+     }
+ 
+  closefiles:
+-  if (ferror (istream) || fclose (istream) == EOF)
++  if (!is_stdin && (ferror (istream) || fclose (istream) != 0))
+     error (EXIT_FAILURE, errno, _("error reading %s"), infile);
+ 
+   /* Close ostream only if it's not stdout -- the latter is closed
+      via the atexit-invoked close_stdout.  */
+-  if (ostream != stdout && (ferror (ostream) || fclose (ostream) == EOF))
++  if (!is_stdout && (ferror (ostream) || fclose (ostream) != 0))
+     error (EXIT_FAILURE, errno, _("error writing %s"), outfile);
+ 
+   free (lb1.buffer);