LP #720547: Implement Logging Certain Errors

**Reported in Launchpad by Peter Zaitsev last update 12-12-2012 05:20:05

Implement an option to be able to log queries with certain error codes to the slow query log (independently of their execution time) this can be used to all queries which caused deadlocks foreign key errors or any over error conditions

log_query_errors=code1,code2,code3 can be used or "all" for all queries with not zero error code.