jsonalchemy: add de_coerce to reverse serialization of list and dict elements from Mutation objects back to original state.

rhodecode/lib/jsonalchemy.py

@@ -99,6 +99,9 b' class MutationObj(Mutable):'
             return MutationList.coerce(key, value)
         return value
 
+    def de_coerce(self):
+        return self
+
     @classmethod
     def _listen_on_attribute(cls, attribute, coerce, parent_cls):
         key = attribute.key
@@ -158,6 +161,9 b' class MutationDict(MutationObj, DictClas'
         self._key = key
         return self
 
+    def de_coerce(self):
+        return dict(self)
+
     def __setitem__(self, key, value):
         # Due to the way OrderedDict works, this is called during __init__.
         # At this time we don't have a key set, but what is more, the value
@@ -188,6 +194,9 b' class MutationList(MutationObj, list):'
         self._key = key
         return self
 
+    def de_coerce(self):
+        return list(self)
+
     def __setitem__(self, idx, value):
         list.__setitem__(self, idx, MutationObj.coerce(self._key, value))
         self.changed()