[examples] Fix and improve test examples

examples/example-test.sb

@@ -5,9 +5,10 @@
     "lilypond",
     "pictures"
   ],
+"lang": "ERROR",
 "booktype" : "chorded",
 "template" : "patacrep.tex",
 "encoding": "utf8",
- "content": ["tests/*.sg", "tests/*.sgc"]
+ "content": ["tests/*.csg", "tests/*.tsg"]
 
 }

examples/songs/tests/errors.csg

@@ -1,4 +1,4 @@
-{lang : en}
+{lang : xx_XX}
 {columns :  2}
 { title : Error}
 {subtitle: A chordpro file with many errors}
@@ -12,4 +12,5 @@ Bla [H]bla
 
 {fo#: bar}
 
-
+{image: foo}
+{partition: bar}