add underline to the section headers

[SVN r24093]

tools/regression/xsl_reports/runner/default.css

@@ -12,6 +12,10 @@ body {
     background-color: #fffff5;
 }
 
+h2 {
+    text-decoration: underline;
+}
+
 .first {
   margin-top: 0 }