This version is intended to replace the old autostatus monitor on bas,
except for monitoring the Mothership itself. We also notify the Slack
channel like the autostatus version. Driven from the apt_aggregates
table in the DB, we do the following.

1. fping all the boss nodes.

2. fping all the ops nodes and dboxen. Aside; there are two special
   cases for now, that will eventually come from the database. 1)
   powder wireless aggregates do not have a public ops node, and 2) the
   dboxen are hardwired into a table at the top of the file.

3. Check all the DNS servers. Different from autostatus (which just
   checks that port 53 is listening), we do an actual lookup at the
   server. This is done with dig @ the boss node with recursion turned
   off. At the moment this is serialized test of all the DNS servers,
   might need to change that latter. I've lowered the timeout, and if
   things are operational 99% of the time (which I expect...