a whole swath of fixes
introduce an authdir_mode() macro to match the others.
don't initialize uptime to the number of seconds since 1970.
non-authoritative dirservers don't cache their directory on disk.
make only authdirservers use clique_mode.
only read approved-routers file if you're an authdirserver.
even authdirservers fetch a new directory in do_hup.
retry_all_connections() is now called retry_all_listeners().
router_parse_list_from_string() correctly reports the router number
it's working on.
only call dirserv_add_own_fingerprint() and
dirserv_add_descriptor() on startup if we're an authdirserver.
if AuthDir and !ORPort then fail.
if AuthDir and ClientOnly then fail.
svn:r2061