Fixed #1662 -- Added resolver for string-form model references for models that have already been loaded, with tests to validate both forward and backward referenced model names. Light refactoring of model loading to make regression tests behave more like normal model loading. Also clarifies the text of some validation errors.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3195 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/runtests.py

@@ -162,10 +162,11 @@ class TestRunner:
         # Initialize the test database.
         cursor = connection.cursor()
 
+        from django.db.models.loading import load_app
         # Install the core always installed apps
         for app in ALWAYS_INSTALLED_APPS:
             self.output(1, "Installing contrib app %s" % app)
-            mod = __import__(app + ".models", '', '', [''])
+            mod = load_app(app)
             management.install(mod)
 
         # Run the tests for each test model.
@@ -173,8 +174,7 @@ class TestRunner:
         for model_dir, model_name in test_models:
             self.output(1, "%s model: Importing" % model_name)
             try:
-                # TODO: Abstract this into a meta.get_app() replacement?
-                mod = __import__(model_dir + '.' + model_name + '.models', '', '', [''])
+                mod = load_app(model_dir + '.' + model_name)
             except Exception, e:
                 log_error(model_name, "Error while importing", ''.join(traceback.format_exception(*sys.exc_info())[1:]))
                 continue