New stuff in 4.2

Important ospfd changes

Carp demotion based on interface or area state
interface state is already tracked
area is considered active if one neighbor is active
 
Mapping of route labels to AS-external route tags and vice versa
AS-external LSA have a 32bit tag
distribute rtlabels on every OSPF router
use for policy distribution when used together with pf
classify a network on the connected router
filter based on the class on all OSPF routers
no need to to maintain pf tables or other network lists