Reported by Thomas McLure.

Thanks to Matthieu Boutier.

Conflicts:
	CHANGES

IANA has changed Babel's allocation to 6696/UDP.

Older Mac OS X doesn't have strnlen.

This is an incompatible babelz protocol change.

We used to recompute this in parse_packet, which is clearly the
wrong place.

The kernel encodes frequency information as a pair of a mantissa and
an exponent.  The previous code only dealt with exponent being 0 or 1.
We now deal with exponents up to 6.

This moves all metric computation back to route.[ch],
where it belongs.

Conflicts:
	CHANGES
	babeld.c
	kernel_socket.c
	network.c
	route.c
	route.h

This is useful in order to provide extra information to a graphic
front-end.  In can cause the RIB to explode in some pathological cases,
so it is not the default.

Working out exactly when to call local_notify_neighbour is too
error-prone.  Call it systematically, at the cost of some extra
local traffic.

This fixes a bug where we forgot to call local_update_neighbour
when receiving an IHU.  Reported by Gabriel Kerneis.

Reported by Gabriel Kerneis.

It triggers fairly often with the new routing changes.

The old name conflicts with autoconf-generated files.

This had never been implemented, we were silently ignoring duplicate
configuration lines.