Pull up following revision(s) (requested by knakahara in ticket #423):

sys/netipsec/key.c: revision 1.268
sys/netipsec/key.c: revision 1.269

Fix SA can be expaired wrongly when there are many SPs.

When key_timehandler_spd() spent over one second, the "now" argument of
key_timehandler_sad() could be older than sav->created. That caused SA
was expired immediately.

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Reduce load for IKE negotiations when the system has many IPv6 addresses.
e.g. the system has many vlan(4), gif(4) or ipsecif(4) with link local address.

(martin)