Modify chord-name-engraver to call capo-handler

input/regression/chord-capo.ly

Index: input/regression/chord-capo.ly
diff --git a/input/regression/chord-capo.ly b/input/regression/chord-capo.ly
new file mode 100644
index 0000000000000000000000000000000000000000..789f47d332d73df8d178be7958e49e30db69e80e
--- /dev/null
+++ b/input/regression/chord-capo.ly
@@ -0,0 +1,28 @@
+\version "2.14.0"
+
+\header{
+  texidoc="Properties capoPitch, capoVertical: display chordnames, suitably 
+transposed for a guitar capo, either in a line or one above the other.
+"
+}
+
+<<
+  \new ChordNames \chordmode {
+    c1
+    g1

[Janek Warchol, 2011/08/02 19:59:06]

I would change all g major chords into a minor chords.

+    c1
+    g1
+    c1
+    g1
+  }
+  \chordmode {
+    c1
+    g1
+    \set ChordNames.capoPitch = #(ly:make-pitch 0 -2 -1/2)
+    c1
+    g1
+    \set ChordNames.capoVertical = ##t
+    c1
+    g1
+  }
+>>