Timeout after max timeout while fetching emails

Processing fetching in ASC order of the last fetch time
Remove LIMIT of 10 emails per fetch
Flush the buffer and terminate the request cleanly on autocron
Merge pull request #468 from protich/feature/mailfetch

Timeout after max timeout while fetching emails

Reviewed-By: Jared Hancock <jared@osticket.com>
Reviewed-By: Alan Wilkes