We want to send emails to SNOs. Node status changes go through the
overlay service, so it's a good place to add the mail service.
Add the mailservice.Service, satellite address, and satellite name to
overlay service. Also add feature flag --overlay.send-node-emails
Change-Id: I3bd2cb3bf22f9724954ce2374f8b651b902b3a24
The flags weren't properly loading from config.
The code assumed that every node that's online for downloading also have
data uploaded to them -- which is not true.
Change-Id: Ifd65a47b9eca5b4841231928244fab17acbde6fb
