Add theme that displays Diffy on the left side of the top menu

Change-Id: Ic2e125f3d7d19cf5d2b07be6e102c28bc814fe17
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

contrib/themes/diffy/etc/GerritSite.css

@@ -0,0 +1,30 @@
+/* Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#gerrit_header {
+  display: block !important;
+  margin-bottom: -55px;
+  padding-left: 20px;
+  position: relative;
+  top: -45px;
+  width: 100px;
+}
+
+#gerrit_topmenu {
+  left: 100px;
+  margin-right: 100px;
+  padding-right: 10px;
+  position: relative;
+}

contrib/themes/diffy/etc/GerritSiteHeader.html

@@ -0,0 +1,3 @@
+<div>
+  <img src="static/logo.png"/>
+</div>