Garden-o-matic: Introduce an option to open links in a new window

Tools/GardeningServer/styles/onebar.css

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 54 matching lines @@
 #chromium-gtests {
     position: absolute;
     top: 10px;
     right: 5px;
 }
 
 #gtest-label {
     vertical-align: top;
 }
 
+#link-handling {
+    position: absolute;
+    top: 10px;
+    right: 0;
+    padding-right: 4px;
+}
+
+#new-window-for-links {
+    vertical-align: text-bottom;
+}
+
 #onebar details {
     padding-left: 2px;
     padding-right: 2px;
     display: inline-block;
     vertical-align: top;
 }
 
 #onebar details table, #revisionPopUp table {
     font-size: 11px;
     text-decoration: none;
@@ skipping 15 matching lines @@
 .topbar {
     display: flex;
     align-items: center;
 }
 
 .treestatus {
     display: inline-block;
     margin: 4px;
     font-size: 11px;
 }