MySQL Escaping Change

Integers are no longer quoted to escape them for insertion into MySQL queries.  They present no risk of SQL injection, and string escaping them means that they cannot be used in LIMIT clauses.
Event Tweak/Fix

Altered the way the IsBackdoor method of the Event class functions: Rather than examining `billdbtable` to determine the backdoor, it will now examine `billUsername`, leading to correct/expected results.