magic-removal:Management fixes. Everything works on app labels, and constraints generation is correct for mutually referential models.

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@1716 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/__init__.py

@@ -14,10 +14,11 @@ from django.db.models.base import Model
 from django.db.models.fields import *
 from django.db.models.fields.related import *
 
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, ImproperlyConfigured
 from django.db.models.exceptions import FieldDoesNotExist, BadKeywordArguments
 from django.db.models.signals import Signals
 
+
 # Admin stages.
 ADD, CHANGE, BOTH = 1, 2, 3
 
@@ -25,8 +26,28 @@ ADD, CHANGE, BOTH = 1, 2, 3
 #def get_module(app_label, module_name):
 #    return __import__('%s.%s.%s' % (MODEL_PREFIX, app_label, module_name), '', '', [''])
 
-#def get_app(app_label):
-#    return __import__('%s.%s' % (MODEL_PREFIX, app_label), '', '', [''])
+def get_models(app):
+    models = []
+    get_models_helper(app, models)
+    return models
+
+def get_models_helper(mod, seen_models):
+    if hasattr(mod, '_MODELS'):
+        seen_models.extend(mod._MODELS)
+    if hasattr(mod, '__all__'): 
+        for name in mod.__all__:
+            sub_mod = __import__("%s.%s" % (mod.__name__, name), '','',[''])
+            get_models_helper(sub_mod, seen_models)
+
+def get_app(app_label):
+    
+    for app_name in settings.INSTALLED_APPS:
+        comps = app_name.split('.')
+        if app_label == comps[-1]:
+            app_models = __import__('%s.models' % app_name , '','',[''])
+            return app_models
+    
+    raise ImproperlyConfigured, "App with label %s could not be found" % app_name
 
 class LazyDate:
     """