refactor title markup and allow songnumbers

eps_file_from_song_dir.ly

@@ -4,15 +4,15 @@
   (interpret-markup-list layout (prepend-alist-chain 'songfilename songfilename props) markuplist))
 
 #(define-markup-command (customEps layout props ysize filename)(number? string?)
-   #:properties ((songfilename "")
-                 (defaultmarkup #f))
+   #:properties ((songfilename ""))
    (interpret-markup layout props
-     (let ((filepath (if (string-null? songfilename)
+     (let ((defaulttitlemarkup (ly:output-def-lookup layout 'defaultTitleMarkup))
+           (filepath (if (string-null? songfilename)
                           filename
                           (ly:format "~a/~a/~a" songPath songfilename filename))))
        (if (file-exists? filepath)
              (make-epsfile-markup Y ysize filepath)
-             (if defaultmarkup
-                 defaultmarkup
+             (if defaulttitlemarkup
+                 defaulttitlemarkup
                  (ly:format "file does not exist ~a" filepath))
 ))))