[PATCH] feature request MASTER_GTID_WAIT status variables

With MASTER_GTID_WAIT I wouldn't mind a global (and optionally session) indication of:

• total time spent in this wait state in including timeouts
• total time spent in the function excluding timeouts
• total number of timeouts occurred in this function

I'd find this quite useful for general health monitoring of this function, particularly when graphed over time.

Thanks for your consideration