Remove "group" identifier from get_index() entries; let the template figure that out.

tests/test_build_latex.py

@@ -87,7 +87,8 @@ def test_latex(app):
             stdout, stderr = p.communicate()
             if p.returncode != 0:
                 print stdout
+                print stderr
                 del app.cleanup_trees[:]
-                assert False, 'latex exited with error'
+                assert False, 'latex exited with return code %s' % p.returncode
     finally:
         os.chdir(cwd)