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 a0929b3..b680c81 100644
--- a/groups
+++ b/groups
@@ -1,3 +1,4 @@
 # UUID                                  	Group Name
 #
 0bc64754b78802646ba7e84fefb836824f744905	Administrators
+global:Registered-Users                 	Registered Users