Display VAT % also in total calculation

Change-Id: I3388813c0246e9412f2a07fae778727bca488286
diff --git a/invoice.php b/invoice.php
index a3bdf08..26edfcf 100644
--- a/invoice.php
+++ b/invoice.php
@@ -83,10 +83,10 @@
     }
 
     /* Add totals */
-    $invoice->addTotal('Net sum', $user->total_due-$vat_sum);
+    $invoice->addTotal('Net Sum', $user->total_due-$vat_sum);
 
     if ($vat_sum > 0) {
-        $invoice->addTotal('+ VAT', $vat_sum, false);
+        $invoice->addTotal("+" . $FULL_VAT * 100 . "% VAT", $vat_sum, false);
     }
     $invoice->addTotal('Total due', $user->total_due, true);