Starts support branch and improve .gitreview

Change-Id: If606144656a9d8882117579d9bb1bc9543eb3d98
diff --git a/.gitreview b/.gitreview
index d765be6..a92bedd 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,5 @@
 port=29418
 project=sadis.git
 defaultremote=origin
+defaultbranch=sadis-3.1
+