Adds compatibility for django 1.10 (gadventures#65)

* Fix gadventures#63: AttributeError: Options object has no attribute get_field_by_name

* Fix gadventures#61: AttributeError: object has no attribute _deferred

fsm_admin/mixins.py

@@ -75,7 +75,7 @@ def fsm_field_instance(self, fsm_field_name):
         Returns the actual state field instance, as opposed to
         fsm_field attribute representing just the field name.
         """
-        return self.model._meta.get_field_by_name(fsm_field_name)[0]
+        return self.model._meta.get_field(fsm_field_name)
 
     def display_fsm_field(self, obj, fsm_field_name):
         """
@@ -225,7 +225,7 @@ def _get_possible_transitions(self, obj):
         """
         fsm_fields = self._get_fsm_field_list()
         for field in fsm_fields:
-            fsmfield = obj._meta.get_field_by_name(field)[0]
+            fsmfield = obj._meta.get_field(field)
             transitions = fsmfield.get_all_transitions(self.model)
             for transition in transitions:
                 if transition.source in [getattr(obj, field), '*']:

fsm_admin/templatetags/fsm_admin.py

@@ -3,6 +3,7 @@
 from django import template
 from django.contrib.admin.templatetags.admin_modify import submit_row
 from django.conf import settings
+from django.db import models
 
 register = template.Library()
 
@@ -47,7 +48,9 @@ def fsm_submit_row(context):
     original = context.get('original', None)
     model_name = ''
     if original is not None:
-        if original._deferred:
+        # TODO: replace the following line by `original is models.DEFERRED`
+        # after dropping support for Django-1.9
+        if getattr(original, '_deferred', False) or original is getattr(models, 'DEFERRED', None):
             model_name = type(original).__base__._meta.verbose_name
         else:
             model_name = original.__class__._meta.verbose_name