bring ospf6d's log.c in sync with ospfd and bgpd
ok florian@ claudio@

From a syslog perspective it does not make sense to log fatal and
warn with the same severity. Switch log_warn() to LOG_ERR and keep
fatal() at LOG_CRIT.
OK reyk@ florian@

copy log.c/h from bgpd.
ok claudio

work on making log.c similar in all daemons:

move daemon-local functions into new logmsg.c, and reduce
the (mostly whitespace) differences so that log.c's can be diffed easily.

ok claudio@, feedback from henning@, deraadt@, reyk@

Convert the logic in yyerror(). Instead of creating a temporary
format string, create a temporary message.
OK deraadt@ claudio@

Unfortunately "ospf6ctl show fib" printed embedded scopes as the
destination addresses still contain them. To fix that, call
recoverscope() in log_in6addr(). Also log_in6addr_scope() should
not fiddle with the scope itself, put that into a generic function
addscope().
OK claudio@

Bring back log_in6addr_scope() as ospf6ctl uses it.
Found by kettenis@ the hard way.

Do not care about the kame hack when logging a link local address.
The scope should have been converted when we received it from kernel.
Remove log_in6addr_scope(), it is not used.
ok claudio@

Decouple log_verbose() from log_init() so the verbose flag stays set with
"-v" (previously only "-vd" worked). Similar to recent ospfd commit.
ok claudio@

Implement log_in6addr_scope() yet another function doing the same thing
again but different because of link local addressing.

Add IMSG_CTL_LOG_VERBOSE similar to ospfd it allows to toggle debug logging.
henning, sthen, michele like the idea

Add log_rtr_id() function to log 32bit numbers in dot-quad notation.
Most obvious use is to log router IDs.
To facilitate logging of multiple IDs within the same format string,
we use NUM_LOGS static buffers, just like log_sockaddr() does.

help and ok claudio@

Switch log_sockaddr() to take a void * so it is not necessary to cast the
sockaddr_in6 or sockaddr_in to a sockaddr.

Use a small cyclic buffer ring in log_in6addr() so that the function can be
used more then once per printf. The current limit is 4.

Welcome ospf6d

The new ospf6d daemon will support OSPFv3, basically OSPF for IPv6 networks.

It is heavily based on ospfd(8), it is more or less a copy and paste of it.
Currently some unneeded stuff has been removed and the trasition from
IPv4 to IPv6 has begun.

ospf6d is not very usefull at the moment, it is being imported to allow more
people to work on it concurrently.

Not yet connected to the builds.

ok claudio@ dlg@