Allow 'query' to be omitted from find*() (fixes #2883)

I hit this in findDocuments() so thought I'd fix them all.

pandora/entity/managers.py

@@ -112,8 +112,9 @@ class EntityManager(Manager):
     def find(self, data, user, item=None):
         #join query with operator
         qs = self.get_query_set()
-        conditions = parseConditions(data['query'].get('conditions', []),
-                                     data['query'].get('operator', '&'),
+        query = data.get('query', {})
+        conditions = parseConditions(query.get('conditions', []),
+                                     query.get('operator', '&'),
                                      user, item)
         if conditions:
             qs = qs.filter(conditions)