Merged regressiontests and modeltests into the test root.

tests/nested_foreign_keys/models.py

@@ -0,0 +1,28 @@
+from django.db import models
+
+
+class Person(models.Model):
+    name = models.CharField(max_length=200)
+
+
+class Movie(models.Model):
+    title = models.CharField(max_length=200)
+    director = models.ForeignKey(Person)
+
+
+class Event(models.Model):
+    pass
+
+
+class Screening(Event):
+    movie = models.ForeignKey(Movie)
+
+class ScreeningNullFK(Event):
+    movie = models.ForeignKey(Movie, null=True)
+
+
+class Package(models.Model):
+    screening = models.ForeignKey(Screening, null=True)
+
+class PackageNullFK(models.Model):
+    screening = models.ForeignKey(ScreeningNullFK, null=True)