For various reasons, this was a nontrivial movement. There are
several places in the code where we do something like "update the
flags on this routerstatus or node if we're an authority", and at
least one where we pretended to be an authority when we weren't.
The main.c code is responsible for initialization and shutdown;
the mainloop.c code is responsible for running the main loop of Tor.
Splitting the "generic event loop" part of mainloop.c from the
event-loop-specific part is not done as part of this patch.
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.
