This code handles the new ORPort options, and incidentally makes all
remaining port types use the new port configuration systems.
There are some rough edges! It doesn't do well in the case where your
Address says one thing but you say to Advertise another ORPort. It
doesn't handle AllAddrs. It doesn't actually advertise anything besides
the first listed advertised IPv4 ORPort and DirPort. It doesn't do
port forwarding to them either.
It's not tested either, it needs more documentation, and it probably
forgets to put the milk back in the refrigerator.
To turn this on, set UseMicrodescriptors to "1" (or "auto" if you
want it on-if-you're-a-client). It should go auto-by-default once
0.2.3.1-alpha is released.
Because of our node logic, directory caches will never use
microdescriptors when they have the right routerinfo available.
It's normal when bootstrapping to have a lot of different certs
missing, so we don't want missing certs to make us warn... unless
the certs we're missing are ones that we've tried to fetch a couple
of times and failed at.
May fix bug 1145.
