Convert all modeltests to use absolute imports, rather than relative ones.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16975 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/modeltests/custom_methods/models.py

@@ -4,9 +4,11 @@
 Any method you add to a model will be available to instances.
 """
 
-from django.db import models
 import datetime
 
+from django.db import models
+
+
 class Article(models.Model):
     headline = models.CharField(max_length=100)
     pub_date = models.DateField()