Changed the inheritance model to remove types

The inheritance model has changed, we no longer need to store an array of
`types` with the model we can just use the classname in `_cls`.

See the upgrade docs for information on how to upgrade
MongoEngine/mongoengine#148

mongoengine/base/datastructures.py

@@ -0,0 +1,124 @@
+import weakref
+
+__all__ = ("BaseDict", "BaseList")
+
+
+class BaseDict(dict):
+    """A special dict so we can watch any changes
+    """
+
+    _dereferenced = False
+    _instance = None
+    _name = None
+
+    def __init__(self, dict_items, instance, name):
+        self._instance = weakref.proxy(instance)
+        self._name = name
+        return super(BaseDict, self).__init__(dict_items)
+
+    def __setitem__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).__setitem__(*args, **kwargs)
+
+    def __delete__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).__delete__(*args, **kwargs)
+
+    def __delitem__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).__delitem__(*args, **kwargs)
+
+    def __delattr__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).__delattr__(*args, **kwargs)
+
+    def __getstate__(self):
+        self.instance = None
+        self._dereferenced = False
+        return self
+
+    def __setstate__(self, state):
+        self = state
+        return self
+
+    def clear(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).clear(*args, **kwargs)
+
+    def pop(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).pop(*args, **kwargs)
+
+    def popitem(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).popitem(*args, **kwargs)
+
+    def update(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseDict, self).update(*args, **kwargs)
+
+    def _mark_as_changed(self):
+        if hasattr(self._instance, '_mark_as_changed'):
+            self._instance._mark_as_changed(self._name)
+
+
+class BaseList(list):
+    """A special list so we can watch any changes
+    """
+
+    _dereferenced = False
+    _instance = None
+    _name = None
+
+    def __init__(self, list_items, instance, name):
+        self._instance = weakref.proxy(instance)
+        self._name = name
+        return super(BaseList, self).__init__(list_items)
+
+    def __setitem__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).__setitem__(*args, **kwargs)
+
+    def __delitem__(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).__delitem__(*args, **kwargs)
+
+    def __getstate__(self):
+        self.observer = None
+        return self
+
+    def __setstate__(self, state):
+        self = state
+        return self
+
+    def append(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).append(*args, **kwargs)
+
+    def extend(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).extend(*args, **kwargs)
+
+    def insert(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).insert(*args, **kwargs)
+
+    def pop(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).pop(*args, **kwargs)
+
+    def remove(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).remove(*args, **kwargs)
+
+    def reverse(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).reverse(*args, **kwargs)
+
+    def sort(self, *args, **kwargs):
+        self._mark_as_changed()
+        return super(BaseList, self).sort(*args, **kwargs)
+
+    def _mark_as_changed(self):
+        if hasattr(self._instance, '_mark_as_changed'):
+            self._instance._mark_as_changed(self._name)