DiagnosticsDialog: Add current time (+ some micro formatting in the log)

src/diagnosticsdialog.cpp

@@ -45,8 +45,11 @@ DiagnosticsDialog::DiagnosticsDialog( QWidget *parent )
 
 void DiagnosticsDialog::updateLogView()
 {
-    QString log(
-        "TOMAHAWK DIAGNOSTICS LOG\n\n"
+    QString log;
+
+    log.append(
+        QString("TOMAHAWK DIAGNOSTICS LOG -%1 \n\n")
+            .arg( QDateTime::currentDateTime().toString() )
     );
 
     // network