12. userportal, webadmin: Add automatic login filter

This patch adds the automatic login filter to the GUI. This doesn't
currently have any effect, as this filter does nothing if the principal
isn't available in the HTTP request. It will have an effect only if at
least one negotiating authenticator is manually configured for the
application

Change-Id: I8a16ee5a30dc1e33cf28cc263f36ea0f5d912845
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>