use fewer ||= lines in the SQL setup
remove some code used to support 4.x < 4.1, seems 4.0.8 (at least) uses the same as 4.1 anyway
efficiency: check the binds before attempting to sanitize/run to_sql on the query
fix support for mysql2 with activerecord 4.1 and above - which requires the bind variables to be present to render the SQL for find(id) calls - at the cost of a little performance