Include unset keys in config obj keys

Also add test to check unset fields

vistrails/core/configuration.py

@@ -37,6 +37,7 @@
 import argparse
 import ast
 import copy
+import itertools
 import re
 import shlex
 import sys
@@ -1438,14 +1439,15 @@ def allkeys(self):
         Returns all options stored in this object.
         """
 
-        return self.db_config_keys_name_index.keys()
+        return self.db_config_keys_name_index.keys() + self._unset_keys.keys()
 
     def keys(self):
         """keys(self) -> list of strings
         Returns all public options stored in this object.
         Public options are keys that do not start with a _
         """
-        return [k for k in self.db_config_keys_name_index
+        return [k for k in itertools.chain(self.db_config_keys_name_index,
+                                           self._unset_keys)
                 if not k.startswith('_')]
 
 # def default():
@@ -1665,6 +1667,11 @@ def test_update(self):
         conf2.showWindow = False
         self.assertTrue(conf1.showWindow)
 
+    def test_unset_params(self):
+        conf = ConfigurationObject(test_field=(None, str))
+        self.assertTrue(conf.is_unset("test_field"))
+        self.assertIn("test_field", conf.keys())
+
     def test_type_mismatch(self):
         conf = default()
         with self.assertRaises(TypeError):