Make arguments like Context.GrobName accessible as symbol lists

Documentation/snippets/score-for-diatonic-accordion.ly

 % DO NOT EDIT this file manually; it is automatically
 % generated from Documentation/snippets/new
 % Make any changes in Documentation/snippets/new/
 % and then run scripts/auxiliar/makelsr.py
 %
 % This file is in the public domain.
 %% Note: this file works from version 2.16.0
-\version "2.17.5"
+\version "2.17.6"
 
 \header {
   lsrtags = "template, real-music, specific-notation"
 
   texidoc = "
 A template to write a score for a diatonic accordion.
 
 - There is a horizontal staff indicating if the accordion must be
 pushed (thick line) or pulled (thin line)
 
@@ skipping 46 matching lines @@
 verse = \lyricmode { Wie gross bist du! Wie gross bist du! }
 
 harmonies = \new ChordNames \chordmode {
   \germanChords
   \set chordChanges = ##t
   bes8 bes8 bes8
   es2 f
   bes1
 }
 
-NoStem = { \override Stem transparent = ##t \override Flag transparent = ##t }
-NoNoteHead = \override NoteHead transparent = ##t
-ZeroBeam = \override Beam  positions = #'(0 . 0)
+NoStem = { \override Stem.transparent = ##t \override Flag.transparent = ##t }
+NoNoteHead = \override NoteHead.transparent = ##t
+ZeroBeam = \override Beam.positions = #'(0 . 0)
 
 staffTabLine = \new Staff \with {
   \remove "Time_signature_engraver"
   \remove "Clef_engraver"
 } {
-  \override Staff.StaffSymbol line-positions = #'(0)
+  \override Staff.StaffSymbol.line-positions = #'(0)
   % Shows one horizontal line. The vertical line (simulating a bar-line) is simulated with a gridline
   \set Staff.midiInstrument = #"choir aahs"
   \key c \major
   \relative c''
   {
     % disable the following line to see the the noteheads while writing the song
     \NoNoteHead
-    \override NoteHead no-ledgers = ##t
+    \override NoteHead.no-ledgers = ##t
 
     % The beam between 8th-notes is used to draw the push-line
     %How to fast write the push-lines:
     %  1. write repeatedly 'c c c c c c c c |' for the whole length of the song
     %  2. uncomment the line \NoNoteHead
     %  3. compile
     %  4. Mark the positions on which push/pull changes.
     %     In the score-picture click on the position the push- or pull-part starts
     %           (on the noteHead, the cursor will change to a hand-icon).
     %     The cursor in the source code will jump just at this position.
@@ skipping 51 matching lines @@
     \Score
     % The vertical line (simulating a bar-line) in
     % the staffBassRhytm is a gridline
     \consists "Grid_line_span_engraver"
   }
   \context {
     \Staff
     \consists "Grid_point_engraver"
     gridInterval = #(ly:make-moment 4 4) % 4/4 - tact. How many beats per bar
     % The following line has to be adjusted O-F-T-E-N.
-    \override GridPoint Y-extent = #'(-2 . -21)
+    \override GridPoint.Y-extent = #'(-2 . -21)
   }
   \context {
     \ChoirStaff
     \remove "System_start_delimiter_engraver"
   }
 }
 
 staffVoice = \new Staff = astaffvoice  {
   \time 4/4
   \set Staff.instrumentName = "Voice"
@@ skipping 15 matching lines @@
   \time 4/4
   \set Staff.instrumentName="Accordion"
   \set Staff.midiInstrument="voice oohs"
   \key c \major
   \clef treble
   { \AccordionTab \bar "|." }
 }
 
 AltOn =
 #(define-music-function (parser location mag) (number?)
-  #{ \override Stem length = #(* 7.0 mag)
-      \override NoteHead font-size =
+  #{ \override Stem.length = #(* 7.0 mag)
+      \override NoteHead.font-size =
 #(inexact->exact (* (/ 6.0 (log 2.0)) (log mag))) #})
 
 AltOff = {
-  \revert Stem length
-  \revert NoteHead font-size
+  \revert Stem.length
+  \revert NoteHead.font-size
 }
 
 BassRhytm = {s4 s8 | c2 c2 | c2 s8 }
 LyricBassRhythmI=  \lyricmode { c b | c }
 
 staffBassRhytm =
 \new Staff = staffbass \with { \remove "Clef_engraver" } {
   % This is not a RhythmicStaff  because it must be possible to append lyrics.
 
-  \override Score.GridLine extra-offset = #'( 13.0 . 0.0 ) % x.y
-  \override Staff.StaffSymbol line-positions = #'( 0 )
+  \override Score.GridLine.extra-offset = #'( 13.0 . 0.0 ) % x.y
+  \override Staff.StaffSymbol.line-positions = #'( 0 )
   % Shows one horizontal line. The vertical line (simulating a bar-line) is simulated by a grid
   % Search for 'grid' in this page to find all related functions
   \time 4/4
   {
     \context Voice = "VoiceBassRhytm"
     \stemDown \AltOn #0.6
     \relative c''
     {
       \BassRhytm
     }
@@ skipping 11 matching lines @@
       \lyricsto melodyVoi \verse
     \staffAccordionMel
     \staffTabLine
     \staffBassRhytm
     \context Lyrics = "lBassRhytmAboveI"
       \with { alignAboveContext = staffbass }
       \lyricsto VoiceBassRhytm \LyricBassRhythmI
   >>
 }
 %}