Refreshing of hosts database on demand

[erikh]

Three ways we could do this:

• Refresh on the interval with the records. We were doing this before and it was causing trouble, but that should be easier to fix now.
• inotify/similar notification systems could help us determine when the file changes, and when to read it.
• refresh on signal or subcommand (which could just send a signal). We talk about control sockets in #1, maybe this is another good use for it.