Fixed self-service links.

In self-service mode the user's association facets have been modified
such that the entries are not linked since the only available entity
is the user entity.

A 'link' parameter has been added to IPA.association_facet and
IPA.column to control whether to link the entries. The link_handler()
method can be used to define how to handle the link.

Ticket #1072

install/ui/group.js

@@ -42,7 +42,7 @@ IPA.entity_factories.group =  function () {
                 {
                     name: 'uid',
                     primary_key: true,
-                    link_entity: true
+                    link: true
                 },
                 {name: 'uidnumber'},
                 {name: 'mail'},