Added vowel transitions for lyrics

lily/hyphen-engraver.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1999--2020 Glen Prideaux <glenprideaux@iname.com>,
   Han-Wen Nienhuys <hanwen@xs4all.nl>,
   Jan Nieuwenhuizen <janneke@gnu.org>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
@@ skipping 117 matching lines @@
       finished_hyphen_ = 0;
     }
 }
 
 void
 Hyphen_engraver::process_music ()
 {
   if (ev_)
     {
       if (ev_->in_event_class("vowel-transition-event"))
-        hyphen_ = make_spanner ("LyricTransition", ev_->self_scm ());
+        hyphen_ = make_spanner ("VowelTransition", ev_->self_scm ());
       else
         hyphen_ = make_spanner ("LyricHyphen", ev_->self_scm ());
     }
 }
 
 void
 Hyphen_engraver::stop_translation_timestep ()
 {
   if (finished_hyphen_ && finished_hyphen_->get_bound (RIGHT))
     {
@@ skipping 11 matching lines @@
   if (hyphen_)
     {
       finished_hyphen_ = hyphen_;
       finished_ev_ = ev_;
     }
 
   hyphen_ = 0;
   ev_ = 0;
 }
 
-
 void
 Hyphen_engraver::boot ()
 {
   ADD_LISTENER (Hyphen_engraver, hyphen);
   ADD_LISTENER (Hyphen_engraver, vowel_transition);
   ADD_ACKNOWLEDGER (Hyphen_engraver, lyric_syllable);
 }
 
 ADD_TRANSLATOR (Hyphen_engraver,
                 /* doc */
                 "Create lyric hyphens, vowel transitions and distance constraints between words.",
 
                 /* create */
                 "LyricHyphen "
                 "LyricSpace "
-                "LyricTransition ",
+                "VowelTransition ",
 
                 /* read */
                 "",
 
                 /* write */
                 ""
                );