Rework the RHN page a little

In order to make room for an Organization field for Sat6, move
the proxy config to a dialog and add the field. Look for
"organization" in the output and let users know they need it if
we catch it being prompted for.

Change-Id: Ic26be8601a3b4eb1a5f2ed58c8dcd07ee3af7890
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1067355
Signed-off-by: Ryan Barry <rbarry@redhat.com>