Add patterns for joining tables in API list methods

i.e. we needed to do an *outer* join on User.person since that can be null

tailbone/templates/users/vue_index.mako

@@ -88,17 +88,18 @@ var app = new Vue({
     data: {
         columns: [
             'username',
-            'person_name',
+            'person_display_name',
             'active'
         ],
         options: {
             filterable: false,
+            headings: {
+                person_display_name: "Person"
+            },
             sortable: [
                 'username',
-                'person_name',
+                'person_display_name',
                 'active'
-                // TODO: add sort for Person.display_name
-                // 'person'
             ],
             orderBy: {
                 column: 'username',