In dirauth:
  * bwauth.c reads and uses bandwidth files
  * guardfraction.c reads and uses the guardfraction file
  * reachability.c tests relay reachability
  * recommend_pkg.c handles the recommended-packages lines.
  * recv_descs.c handles fingerprint files and processing incoming
    routerinfos that relays upload to us
  * voteflag.c computes flag thresholds and sets those thresholds on
    routerstatuses when computing votes

In control:
  * fmt_serverstatus.c generates the ancient "v1 server status"
    format that controllers expect.

In nodelist:
  * routerstatus_fmt.c formats routerstatus entries for a consensus,
    a vote, or for the controller.

(from #20874 fix)

I am very glad to have written this script.

This commit won't build yet -- it just puts everything in a slightly
more logical place.

The reasoning here is that "src/core" will hold the stuff that every (or
nearly every) tor instance will need in order to do onion routing.
Other features (including some necessary ones) will live in
"src/feature".  The "src/app" directory will hold the stuff needed
to have Tor be an application you can actually run.

This commit DOES NOT refactor the former contents of src/or into a
logical set of acyclic libraries, or change any code at all.  That
will have to come in the future.

We will continue to move things around and split them in the future,
but I hope this lays a reasonable groundwork for doing so.

or.h should really include only the minimum of stuff from or/*,
common/*, and lib/*.

I was expecting this to be much worse.

This will yield different error codes for transient and permament
errors. Furthermore, Tor will give human readable error
messages to controller.

When the fascist_firewall_choose_address_ functions don't find a
reachable address, set the returned address to the null address and port.

This is a precautionary measure, because some callers do not check the
return value.

Fixes bug 24736; bugfix on 0.2.8.2-alpha.

Also make IPv6-only clients wait for microdescs for relays, even if we were
previously using descriptors (or were using them as a bridge) and have
a cached descriptor for them.

But if node_is_a_configured_bridge(), stop waiting for its IPv6 address in
a microdescriptor, because we'll never use it.

Implements #23827.

Make the "Exit" flag assignment only depend on whether the exit
policy allows connections to ports 80 and 443. Previously relays
would get the Exit flag if they allowed connections to one of
these ports and also port 6667.

Resolves ticket 23637.

I think this one probably can't underflow, since the input ranges
are small.  But let's not tempt fate.

This patch also replaces the "cmp" functions here with just "eq"
functions, since nothing actually checked for anything besides 0 and
nonzero.

Related to 21278.

teor authored Feb 01, 2017 and Nick Mathewson committed Feb 01, 2017

This disregards anything smaller than an IPv6 /64, and rejects ports that
are rejected on an IPv6 /16 or larger.

Adjust existing unit tests, and add more to cover exceptional cases.

No IPv4 behaviour changes.

Fixes bug 21357