Assign default permissions on user branches

By default each user should be able to read and update the own user
branch. Also the user should be able to approve and submit changes for
the own user branch. Assign default permissions for this and remove the
old exclusive read protection from the user branches.
diff --git a/groups b/groups
index 3e15e53..62702ec 100644
--- a/groups
+++ b/groups
@@ -1,3 +1,4 @@
 # UUID                                  	Group Name
 #
 61317511a4a11254cbbf9612896412663548965a	Administrators
+global:Registered-Users                 	Registered Users