* The previous checks for interruptions only helped in a few corner cases
  like for very high search-repeat counts or during backwards searches across
  the entire buffer.
* But even with terex' more predictable runtime properties
  a single regex execution can hang quite a long time.
  E.g. `S^EM^X$` on a huge buffer or even more so with backreferences as in
  `S^~(.*)\1$`.
* We now use the new tere_set_is_interrupted_cb() to register
  teco_interface_is_interrupted(). Types should be compatible as long
  as gboolean resolves to int.
* It's no longer necessary to manually check for teco_interface_is_interrupted()
  since tere_exec() now returns REG_EINTR in case the callback returned TRUE
  in which case it's handled by teco_error_regex_set().

* terex is based on Henry Spencer's regular expression engine for Tcl.
  It is a hybrid NFA/DFA design which has better worst-time runtimes than
  the backtracking PCRE. Memory usage is also limited and can no longer
  increase catastrophically.
* It should no longer be possible to crash SciTECO with pathological
  searches.
* Since it reliably supports partial matches (REG_EXPECT) we can
  now enable the new backwards-search algorithm by default.
  This used to be broken because of a glib bug, which I already
  fixed. It would however take a long time until this ends up
  on the majority of glib installations.
* Regexp executions can still be quite slow if you are looking
  for a pattern at the end of a huge file, which can hang the editor,
  but this can now at least theoretically be solved by adding
  hooks into terex to poll for interruptions.
* We can now also get rid of a TECO-pattern to regexp translation
  step by directly generating terex tokens (TODO).
* Performance-wise terex appears to be slower than PCRE for simple
  forward searches even when linking everything with optimzations (FIXME).
* Having a stand-alone regular expression engine is also a huge
  step in getting rid of glib.

See also: https://git.fmsbw.de/terex/about/

* The terminal's default foreground and background colors
  are now used by default (`sciteco --no-profile`), so SciTECO
  integrates naturally into all terminal color schemes, even
  dark-on-bright ones.
* The default Scintilla colors use only 0x000000 (COLOR_BLACK) and 0xC0C0C0 (COLOR_WHITE)
  now.
* You can use `7EJ` to configure the default colors in color
  schemes or your profile.
  All existing color schemes had to disable default colors
  (`-1,-1,7EJ`) since they wouldn't look well otherwise.
* You may add `-1,7EJ` to ~/.teco_ini when using a terminal emulator
  with a washed-out palettized COLOR_BLACK.
  We cannot detect the terminal's default colors automatically.
* Scinterm updated to v6.0.
  We require a not-yet-upstreamed patch:
  https://github.com/orbitalquark/scinterm/pull/40
* In fact, we might decide not to support default colors at all in Scinterm,
  so this feature should be considered experimental.

* Instead of supporting only 16 predefined RGB placeholder
  values in Scintilla messages and styles, you can now use
  arbitrary RGB values and colors are allocated via the terminal
  on the fly.
  You no longer need to call 3EJ to change the default color
  palette.
* The placeholder RGB values are still available.
  Since you will usually want exact RGB values when using
  anything outside of the range of 16 default colors
  and the RGB placeholders will not always exactly correspond
  to their RGB value, you can now call `0,3EJ` to ignore
  the default palette and allocate all colors dynamically.
* Allows for more than 16 colors on the screen simultaneously.
  Also simplifies the solarized.tes color scheme.
  Since both Scinterm and SciTECO try not to touch the 16
  default colors, you also no longer have to deal with
  restoring the palette after program termination
  (which was never reliable anyway).
* Color schemes with non-default colors (solarized.tes)
  may now be broken on TERM=linux-16color (Linux VT)
  since Scinterm will get only 8 colors, but solarized.tes
  needs 16.

* ubuntu22-appimage still cannot be built with buildah.
* But at least CI goes through now with PDCursesMod v4.5.4.

This is useful to launch from a terminal without "blocking" this terminal.
There are tools like nohup and daemonize (BSD) to do the same, but having it
builtin is shorter to write.