added new repositories for mcp salt and extra

Change-Id: Id279804a0af7d55481ffaefe3c0c498ff50be510
diff --git a/linux/system/repo/saltstack_2016_3_xenial.yml b/linux/system/repo/saltstack_2016_3_xenial.yml
index 6fed4c5..413294f 100644
--- a/linux/system/repo/saltstack_2016_3_xenial.yml
+++ b/linux/system/repo/saltstack_2016_3_xenial.yml
@@ -1,3 +1,4 @@
+##Obsolete, please use repo/saltstack/xenial
 parameters:
   linux:
     system: