* When fixing up hash-bang lines, `::FS` returns a status integer, which was returned by the process
* also avoid expanding Make variables into TECO code - better pass it as a command-line argument
* should also fix OBS builds

* hash-bang lines in grosciteco.tes and tedoc.tes are fixed up
  at build time instead of install-time (via install-exec-hook).
* This will hopefully resolve problems with the FreeBSD port,
  since Poudriere installs the package as non-root but with BINMODE=555.
  The alternative would have been to set BINMODE=755 in the port which may not
  be acceptible by the official port committer.
  Anyway, I decided to go out of the way of any conflicts.
  See also https://bugs.freebsd.org/bugzilla/show_bug.cgi?format=multiple&id=283601
* On the downside, this will break install-path overrides at install-time
  (e.g. `make install bindir=...`).

* grosciteco.tes generates two output files.
  First this was modeled with `%.woman %.woman.tec : ...`, but it creates independant rules
  which could result in superfluous builds and broke parallel builds.
  Then I tried grouped targets (`%.woman %.woman.tec &: ...`) which were supposed to solve the
  problem cleanly. However they turned out to be buggy with pattern rules,
  so I used templates instead.
  Unfortunately grouped targets turned out to be unreliable in general and that broke
  some older platforms, resulting in broken .woman.tec files.
* The same can be achieved by declaring .woman files the main artifact and
  having an empty rule like `%.woman.tec : %.woman;`.
  If anything draws in .woman.tec, it will still execute the rule only once.

Hopefully fixes the Mac OS CI and nightly builds.

* There were two rules with independent targets, which could
  result in `.woman.tec` files to actually contain plain text.
  Practically all parallel builds were affected, among other
  things OBS-built packages where tutorial.woman.tec would
  usually be broken.
* Now use the `&:` syntax for grouped targets.

* They have a newer version in pkgsrc, but it's not even available
  as a binary package on the arm6.
* Has some glitches, e.g. does accept the ASCII 27 in tutorial.ms,
  but it's probably not worth to work around.

* The previous way of fixing up all `*.tes` scripts had the disadvantage
  of touching unrelated scripts or grosciteco/tedoc of a previous invocation.
  E.g. installing a Gtk build after the ncurses build would overwrite all hash-bang
  lines of the curses-version scripts as well with gsciteco.
* This caused problems with the RPM package where both variants were
  installed into the same buildroot and introduced a dependency from sciteco-curses
  to sciteco-gtk.
  This is worked around in sciteco.spec with a manual sed call.
* It would be better to get rid of the install-exec-hook altogether
  as it causes problems with FreeBSD/Poudriere (FIXME).

* They would get the --program-prefix.
* If they aren't installed as real scripts, there is no point in fixing up their
  hash-bang lines.
* The hash-bang line fix won't work on Windows anyway, so they are now disabled for
  grosciteco and tedoc as well.

* The unnamed buffer is also used for reading from --stdin, so you couldn't practically combine
  --stdin with passing command-line arguments to macros.
* The old approach of passing command-line arguments via lines in the
  unnamed buffer was flawed anyway as it wouldn't work with filenames containing LF.
  This is just a very ancient feature, written when there weren't even long Q-reg names in SciTECO.
* You can now e.g. pipe into SciTECO and edit what was read interactively, e.g. `dmesg | sciteco -i`.
  You can practically use SciTECO as a pager.
* htbl.tes is now a command-line filter (uses -qio).
* grosciteco.tes reads Troff intermediate code from stdin, so we no longer need
  "*.intermediate" temporary files.
* added a getopt.tes test case to the testsuite.
* This change unfortunately breaks most macros accepting command-line arguments,
  even if they used getopt.tes.
  It also requires updating ~/.teco_ini - see fallback.teco_ini.

* htbl.tes now reads from stdin and writes to stdout.
  Allows avoiding temporary `*.htbl` files
* grosciteco.tes still cannot be simplified since --stdin cannot be combined with
  passing command-line arguments (FIXME).