To be consistent with other daemons.

Although standard says that if we receive AS_PATH_CONFED_*
(and we are not a part of a confederation) segment, we should
drop session, nobody does that and it is unwise to do that.

Now we drop session just in case that peer ASN is in
AS_PATH_CONFED_* segment (to detect peer that considers BIRD
as a part of its confederation).

If other side of a socket is sending data faster than
BIRD is processing, BIRD does not schedule any other
callbacks (events, timers, rx/tx callbacks).

Also does some reorganization in RT LSA announcement.

The difference is here to reject incoming connections in the
first case.

This also ensures that misconfigured routers (one side
ptp and one side broadcast) do not make adjacency.

ea_same() sometimes returns true for different route attributes,
which caused that hash table in BGP does not work correctly and
some routes were sent with different attributes.