Git revision info comes now out of a tex file.

The variant developed on a Windows system didn't work on a Archlinux system.
Now the Makefile creates a file 'revision.tex' which the main latex file inputs as revision number.
Hopefully this will do the trick on both systems.

notes/Buergerlied.ly

@@ -7,7 +7,7 @@
 
 <<  
   \chords {s4 g2 e1*3/4:m g2 c1*3/4:7 a2:m d1*3/4:7 g2 c1*3/4:7 a2:m d1*3/4:7 e4:m a2:m g e4:m a2:m g}
-  \relative d''
+  \relative d'
   {
     \time 5/4
     \key g \major