Binlog Alerting

This pull request has just the binlog alerting changes; it reports the binlog position, and throws an alert if the binlog hasn't advanced in a specified-through-options time window.  This is more reliable than using the seconds-behind-master metric, which is a) only a rough approximation, and b) will remain at 0 even in some situations where replication has stopped (e.g. network disconnected).  

Only merge this if you like the, but DON'T like the hourly ignore; I'm making a separate pull request that includes the two already-merged together, so you don't have to do the work.