Use query_son directly to support newer pymongo

debug_toolbar_mongo/__init__.py

 # following PEP 386, versiontools will pick it up
-__version__ = (0, 1, 5, "final", 0)
+__version__ = (0, 1, 6, "final", 0)

debug_toolbar_mongo/operation_tracker.py

 import functools
-import traceback
 import time
 import inspect
 import os
@@ -168,7 +167,7 @@ def _cursor_refresh(cursor_self):
         # Normal Query
         query_data['skip'] = privar('skip')
         query_data['limit'] = privar('limit')
-        query_data['query'] = query_son.get('$query')
+        query_data['query'] = query_son.get('$query') or query_son
         query_data['ordering'] = _get_ordering(query_son)
 
     queries.append(query_data)