Release 0.9:
- add Lang.registered_langs
- add (Title n) token, may be useful for markdown for example
- OCaml lexer now handles nested comments
- add Lang.parse_lexbuf
- change Lang.token type to add length of token text

Release 0.8:
- Depend on Xtmpl 0.19.0
- Use dune to build and install
- Lexers use Sedlex instead of ulex

Release 0.7:
- depend on ocaml 4.12.0 and xtmpl 0.18.0
- fix highlight of %id to handle capitalized ids and ids with dots

Release 0.6:
- OCaml lexer: use same keyword level for %lwt as for other %id
- OCaml lexer: fix highlight of %id (% was removed except for %lwt)

Release 0.5:
- add json and dot lexers
- support "nonrec" keyword in ocaml lexer
- use Xtmpl >= 0.13
- OCaml lexer: handle %id as Keyword 5

Release 0.4:
- safe-string mode
- OCaml lexer: fix #2: bad lexing of directives on first line
- OCaml lexer: handle Lwt keywords as Keyword 10

Release 0.3:
- new higlo tool
- new mk-higlo script

Release 0.2:
- ocaml lexer: handle toplevel directives
- META: add separate packages higlo.ocaml and higlo.xml,
  required by higlo.lexers

