* 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.

* This is mainly to support Scinterm 6.0, which does not appear to
  work with older Scintilla versions (obviously a bug).
* SCI_SETTABDRAWMODE(SCTD_CONTROLCHAR) has been merged upstream
* SC_LINE_END_TYPE_NONE will not be merged and may have to be
  permanently maintained.

* 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.

* Scinterm was simply rendering them as black, thus effectively
  breaking the Linux and FreeBSD vts with terminal.tes.
* I was considering to render light black as white on 8-color terminals,
  so it's always readable.
  However, if you add in A_BOLD there is a good chance that the
  color will end up grey - at least it does in the virtual terminals (consoles).
* There is no need to use bright colors in the Scintilla view defaults.
  E.g. 0xFFFFF is "light white".
  However on 8-color terminals this will be rendered like white anyway.
  The new defaults are closer to what terminal.tes does.

Will rarely be of use in SciTECO, but it's part of the officially merged commit.

* Hopefully also fixed FreeBSD CI builds. Always define NCURSES_WIDECHAR.
* Windows builds were probably also broken.
  We now pass down PDC_WIDE and PDC_FORCE_UTF8 into Scinterm as well.

This is for some minor cleanup.

Also, Scinterm had to be updated again since NetBSD curses stores up to 8 wchar_t per cell.

* Also updated A_XXX attributes to WA_XXX, where the "new" wattr_set() APIs
  are used. This doesn't make a difference on ncurses and PDCurses, but the
  X/Open standard demands it.
* Allow color pairs up to 32767 instead of only up to 32766.
* We now always require Curses wide-character APIs due to Scinterm,
  which has to use mvwin_wch(). We were practically depending on wide-character
  support anyway, so this shouldn't really restrict portability.
* teco_curses_add_wc() has been simplified, now that we can rely on
  wide-char APIs. Perhaps it should be removed altogether?