Add forgotten fields to merge_ifconf.
Fix flush_all_routes : wasn't uninstalling the right one.
Explicitly set rp_filter for all interfaces.

It turns out that the rp_filter is only disabled if both all/rp_filter
and ifname/rp_filter are set to 0.  This sets and restores all of these
values explicitly, which fixes mysterious issues on distributions that
set rp_filter by default.

Conflicts:
	kernel_netlink.c
Update CHANGES for 1.3.8.