Issue 630: non-synchronized grace note makes voiceOne go stems down

Documentation/ly-examples/tab-example.ly

-\version "2.19.2"
+\version "2.19.16"
 
 #(define (glissando::calc-extra-dy grob)
    (let* ((original (ly:grob-original grob))
           (left-bound (ly:spanner-bound original LEFT))
           (right-bound (ly:spanner-bound original RIGHT))
           (left-pitch (ly:event-property (event-cause left-bound) 'pitch))
           (right-pitch (ly:event-property (event-cause right-bound) 'pitch)))
 
      (if (and (= (ly:pitch-octave left-pitch) (ly:pitch-octave right-pitch))
               (= (ly:pitch-notename left-pitch) (ly:pitch-notename right-pitch)))
          (- (ly:pitch-alteration right-pitch) (ly:pitch-alteration left-pitch))
          0 )))
 
 upper= \relative c' {
   \time 4/4
   \key e \major
   \set Staff.midiInstrument = #"acoustic guitar (steel)"
   \set fingeringOrientations = #'(left)
 
-  \partial 4. cis8 e4
+  \partial 4. \acciaccatura c16 \glissando cis8 e4
   < cis-1 g'-3 >2 s8 \grace a16 ( \glissando < b-2 >8\3 ) < d-1 > ( b )
   < e-3 >\2 ( <d-1> b ) \grace < ais-2 >16 ( \glissando a8 g ) s4.
   s4. < d'\3 g\2 >8 < gis,\4  d'\3 fis\2 >2\arpeggio ~
   < gis\4 d'\3 fis\2 >2 < b'\2\harmonic e\harmonic >2\fermata
 }
 
 lower= \relative c {
   \set fingeringOrientations = #'(left)
 
   \partial 4. s4.
@@ skipping 32 matching lines @@
     \context {
       \Staff
       \hide StringNumber
     }
     \context {
       \TabStaff
       \revert Arpeggio.stencil
     }
   }
 }