add stencil-whiteout-outline function

scm/bar-line.scm

 ;;;; This file is part of LilyPond, the GNU music typesetter.
 ;;;;
 ;;;; Copyright (C) 2009--2015 Marc Hohl <marc@hohlart.de>
 ;;;;
 ;;;; 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
 ;;;; (at your option) any later version.
 ;;;;
 ;;;; LilyPond is distributed in the hope that it will be useful,
@@ skipping 453 matching lines @@
 
     stencil))
 
 (define (make-kievan-bar-line grob extent)
   "Draw a kievan bar line."
   (let* ((font (ly:grob-default-font grob))
          (stencil (stencil-whiteout-box
                    (ly:font-get-glyph font "scripts.barline.kievan"))))
 
     ;; the kievan bar line has no staff lines underneath,
-    ;; so we whiteout them and move the grob to a higher layer
+    ;; so we whiteout-box them and move the grob to a higher layer
     (ly:grob-set-property! grob 'layer 1)
     stencil))
 
 (define ((make-bracket-bar-line dir) grob extent)
   "Draw a bracket-style bar line. If @var{dir} is set to @code{LEFT}, the
 opening bracket will be drawn, for @code{RIGHT} we get the closing bracket."
   (let* ((thick-stil (make-thick-bar-line grob extent))
          (brackettips-up (ly:font-get-glyph (ly:grob-default-font grob)
                                             "brackettips.up"))
          (brackettips-down (ly:font-get-glyph (ly:grob-default-font grob)
@@ skipping 589 matching lines @@
 (allow-volta-hook ":..:")
 (allow-volta-hook ":|.|:")
 (allow-volta-hook ":|.:")
 (allow-volta-hook ".|")
 (allow-volta-hook ":|.S")
 (allow-volta-hook ":|.S-S")
 (allow-volta-hook ":|.S.|:")
 (allow-volta-hook ":|.S.|:-S")
 (allow-volta-hook ":|]")
 (allow-volta-hook ":|][|:")