Fix Database().create_query() to actually initialize the Query with the correct object.

We were passing the internal pointer to the notmuch_database_t object to Query(), but it should be initialized with the Database() object itself. This rightfully raised an exception. Yay, for thorough sanity checking.

cnotmuch/database.py

@@ -314,7 +314,7 @@ class Database(object):
         # Raise a NotmuchError if not initialized
         self._verify_initialized_db()
 
-        return Query(self._db, querystring)
+        return Query(self, querystring)
 
     def __repr__(self):
         return "'Notmuch DB " + self.get_path() + "'"