* The main interface is the `FT` command.
  `FT` was an undocumented Video TECO command for etags/ctags lookups.
  I don't want to exactly copy its interface, though.
* `FT` allows looking up symbol names,
  definitions and references.
* ctags will be supported via ctags-lsp.
  LSP support is more powerful though and works without
  regenerating TAGS files all the time.
  The LSP will also allow you to customize auto-completions
  using SciTECO itself (i.e. by writing a language server
  in SciTECO).
* For multiple results, `FT$` can be used to cycle through
  results - this should mimic repeated `S$` or `N$`.
* `:FT...$` does a fuzzy search. IMHO it's not important
  to return a status integer instead. `FT` will only
  really be used in interactive mode.
* Document synchronization is supported via hooks from
  ring.c and via Scintilla notifications.
* Currently, the LSP communication is based on blocking
  GIOChannels. This means that a misbehaving hanging
  server could "lock up" the entire editor (FIXME).
  Only on ncurses you can always kill the subprocess by
  pressing CTRL+C.
  We need helper functions in spawn.c to read and write
  with interruptions.
* The textDocument/didChange notification transmits
  not only all edits, but all files' contents as well
  during initial synchronization.
  Therefore it is optimized to write and JSON-escape
  data without copying them around in memory and without
  destroying the buffer gap.
* Use $SCITECO_LSP to configure the language server.
  You can also use `tee` to capture stdin and stdout.
  Perhaps $SCITECO_LSP should be saved in .teco_session,
  so you can change it between projects?
* $SCITECO_LSP_ROOT is used to point to the project's
  root directory. session.tes will set it up automatically.

* 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 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).

There will be a lot more commands for terminal/message
input and output soon.

* This made sense to include both `W` and `V`, so we also included `D` and `K`.
  `^Q` is included since it converts between lines and glyphs.
* These are all single-letter commands, so they aren't complete parser states
  but callbacks to be referenced in teco_machine_main_transition_t.

* this works by embedding the SciTECO parser and driving it always (exclusively)
  in parse-only mode.
* A new teco_state_t::style determines the Scintilla style for any character
  accepted in the given state.
* Therefore, the SciTECO lexer is always 100% exact and corresponds to the current
  SciTECO grammer - it does not have to be maintained separately.
  There are a few exceptions and tweaks, though.
* The contents of curly-brace escapes (`@^Uq{...}`) are rendered as ordinary
  code using a separate parser instance.
  This can be disabled with the lexer.sciteco.macrodef property.
  Unfortunately, SciTECO does not currently allow setting lexer properties (FIXME).
* Labels and comments are currently styled the same.
  This could change in the future once we introduce real comments.
* Lexers are usually implemented in C++, but I did not want to draw in C++.
  Especially not since we'd have to include parser.h and other SciTECO headers,
  that really do not want to keep C++-compatible.
  Instead, the lexer is implemented "in the container".
  @ES/SCI_SETILEXER/sciteco/ is internally translated to SCI_SETILEXER(NULL)
  and we get Scintilla notifications when styling the view becomes necessary.
  This is then centrally forwarded to the teco_lexer_style() which
  uses the ordinary teco_view_ssm() API for styling.
* Once the command line becomes a Scintilla view even on Curses,
  we can enabled syntax highlighting of the command line macro.

* should also fix Win32 nightly builds
* Even though we weren't using main's argv, but were using glib
  API for retrieving the command line in UTF-8, newer MinGW runtimes
  would fail when converting the Unicode command line into the system codepage
  would be lossy.
* Most people seem to compile in a "manifest" to work around this issue.
  But this requires newer Windows versions and using some Microsoft tool which isn't
  even in $PATH.
  Instead, we now link with -municode and define wmain() instead, even though we still
  ignore argv. wmain() proabably get's the command line in UTF-16 and we'd have to
  convert it anyway.
* See https://github.com/msys2/MINGW-packages/issues/22462

* significantly speeds up build time
* Scintilla and Lexilla headers and symbols are all-ASCII anyway.
* We should probably have a look at the quicksort implementation
  in string.tes, as it can probably be optimized in UTF-8 documents as well.

* You no longer have to copy contrib/scintilla, contrib/scinterm and contrib/lexilla
  manually to the build directory.
* It turns out, that Scintilla/Lexilla was supporting this since 2016.
  Scintilla allows pointing to a source directory (srdir) and Lexilla to a binary directory (DIR_O).
* For Scinterm I opened a pull request in order to add srcdir/basedir variables:
  https://github.com/orbitalquark/scinterm/pull/21
* `make distcheck` is therefore now also fixed.
* The FreeBSD package is now allowed to build out of source.
  I haven't tested it yet.
* See also https://github.com/ScintillaOrg/lexilla/issues/266