If you have projects in different languages you can set different LSPs.
The default will still come from ~/.teco_ini if you decide to set one.
The default for $SCITECO_LSP_ROOT is set by session.tes' VCS integration
based on the VCS root, but you could still overwrite it per session.

* 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.

* Improves DEC TECO-11 compatibility.
* <EM> is still supported as a synonym, but considered deprecated and is no longer documented.
  A warning is printed when invoked.
  It can be repurposed at any time in the future.
* `EI$` is not yet supported.
  I am unsure whether this makes any sense.

* This is rendered with ms, so we now need the entire groff on Debian.
  This is not a big deal as it just adds a few kilobytes of build-time dependencies.
  Most platforms do not allow installation of some "groff-base" package anyway
  and always draw in the entire package.
* sciteco.tmac has been extended to disable page breaks on ms.
* The tutorial is installed like any other woman page and can be invoked
  interactively with ?tutorial$.
* It is optimized to be still usable on a plain 80x24 terminal.

* This goes into session.vcs as well.
* `fossil info` does not allow printing only the local-root property, so we have to do
  some parsing afterwards.

* In fact, since SVN has --no-newline, this is even simpler than on Git and Mercurial.
* This requires at least Subversion v1.9 (2015, so should be safe).

* The previous convention of !* ... *! are now true block comments,
  i.e. they are parsed faster, don't spam the goto table and allow
  embedding of exclamation marks - only "*!" terminates the comment.
* It is therefore now forbidden to have goto labels beginning with "*".
* Also support "!!" to introduce EOL comments (like C++'s //).
  This disallows empty labels, but they weren't useful anyway.
  This is the shortest way to begin a comment.
* All comment labels have been converted to true comments, to ensure
  that syntax highlighting works correctly.
  EOL comments are used for single line commented-out code, since it's
  easiest to uncomment - you don't have to jump to the line end.
  This is a pure convention / coding style.
  Other people might do it differently.
* It's of course still possible to abuse goto labels as comments
  as TECO did for ages.
* In lexing / syntax highlighting, labels and comments are highlighted differently.
* When syntax highlighting, a single "!" will first be highlighted as a label
  since it's not yet unambiguous. Once you type the second character (* or !),
  the first character is retroactively styled as a comment as well.

* You can now set a per-file tab style, that differs from the defaults established
  in the ED hook.
  This is important especially since we do not yet support per-project .teco_ini
  scripts where you could establish differing policies depending on the VCS repository.
  (The latter would be easy to implement, but we cannot currently easily extend the
  existing ED hooks.)
* It's unlikely that files contain an ASCII 27, but not impossible.
  Therefore we now use ASCII 0 (^@) as a terminator.
  This indeed be safe under UNIX.
  Even better would be a string building construct for escaping ASCII 27 ($), though,
  as that would work with arbitrary bytes.

 * globbing is fnmatch(3) compatible, now on every supported platform.
 * which means that escaping of glob patterns is possible now.
   ^ENq has been introduced to ease this task.
 * This finally allows you to pass unmodified filenames to EB.
   Previously it was impossible to open file names containing glob wildcards.
 * this was achieved by moving from GPattern to GRegex as the underlying
   implementation.
 * The glob pattern is converted to a regular expression before being
   compiled to a GRegex.
   This turned out to be trickier than anticipated (~140 lines of code)
   and has a runtime penalty of course (complexity is O(2*n) over the
   pattern length).
   It is IMHO still better than the alternatives, like importing
   external code from libiberty, which is potentially non-cross-platform.
 * Using GRegex also opens the potential of supporting brace "expansions"
   later in the form of glob pattern constructs
   (they won't actually expand but match alternatives).
 * is_glob_pattern() has been simplified and moved to Globber::is_pattern().
   It makes sense to reuse the Globber class namespace instead of using
   plain functions for functions working on glob patterns.
 * The documentation has a new subsection on glob patterns now.
 * Testsuite extended with glob pattern test cases

 * turned out to be a very handy feature
 * can be turned off by setting register `session.savedir` to false
 * also fixed the line endings in .teco_session files to line-feed (ie. native)