Get rid of eval in metadata type default and lookup fields. gh-issue #151.

mayan/apps/user_management/apps.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+from django.contrib.auth import get_user_model
 from django.contrib.auth.models import User, Group
 from django.utils.translation import ugettext_lazy as _
 
@@ -7,6 +8,7 @@ from actstream import registry
 
 from common import menu_multi_item, menu_object, menu_secondary, menu_setup
 from common.apps import MayanAppConfig
+from metadata import MetadataLookup
 from rest_api.classes import APIEndPoint
 
 from .links import (
@@ -28,6 +30,9 @@ class UserManagementApp(MayanAppConfig):
 
         APIEndPoint('users', app_name='user_management')
 
+        MetadataLookup(description=_('All the groups.'), name='group', value=Group.objects.all())
+        MetadataLookup(description=_('All the users.'), name='users', value=get_user_model().objects.all())
+
         menu_multi_item.bind_links(
             links=[link_group_multiple_delete],
             sources=['user_management:group_list']