Added support for stacked inline models.

Added highlighting to sorted inline.
Added migrations to add Note class to database.
Added SortableInlineBase for checking type of model specified in inline model subclasses Sortable.

sample_project/app/migrations/0002_add_note.py

@@ -0,0 +1,59 @@
+# encoding: utf-8
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        
+        # Adding model 'Note'
+        db.create_table('app_note', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('order', self.gf('django.db.models.fields.PositiveIntegerField')(default=1, db_index=True)),
+            ('project', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['app.Project'])),
+            ('text', self.gf('django.db.models.fields.CharField')(max_length=100)),
+        ))
+        db.send_create_signal('app', ['Note'])
+
+
+    def backwards(self, orm):
+        
+        # Deleting model 'Note'
+        db.delete_table('app_note')
+
+
+    models = {
+        'app.category': {
+            'Meta': {'ordering': "['order', 'id']", 'object_name': 'Category'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'title': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'app.credit': {
+            'Meta': {'ordering': "['order', 'id']", 'object_name': 'Credit'},
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'project': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Project']"})
+        },
+        'app.note': {
+            'Meta': {'ordering': "['order', 'id']", 'object_name': 'Note'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'project': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Project']"}),
+            'text': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'app.project': {
+            'Meta': {'ordering': "['order', 'id']", 'object_name': 'Project'},
+            'category': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Category']"}),
+            'description': ('django.db.models.fields.TextField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'title': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        }
+    }
+
+    complete_apps = ['app']