MFC 244325:

- Fix strtol() error handling.
- Add a range condition of given FIB number and the related error messages.
- Fix free() problem.
MFC 245168:

Fix -iface and -interface modifiers.
MFC 251581:

Fix a bug that the gateway address was not shown when a -gateway modifier
was used.
MFC 251584:

Add :ifname modifier to specify interface-specific routes into
{,ipv6_}static_routes and rc.d/routing.  For example:

 static_routes="foo bar:em0"
 route_foo="-net 10.0.0.0/24 -gateway 192.168.2.1"
 route_bar="-net 192.168.1.0/24 -gateway 192.168.0.2"

At boot time, all of the static routes are installed as before.
The differences are:

- "/etc/rc.d/netif start/stop <if>" now configures static routes
  with :<if> if any.
- "/etc/rc.d/routing start/stop <af> <if>" works as well.  <af> cannot be
  omitted when <if> is specified, but a keyword "any" or "all" can be used
  for <af> and <if>.
MFC 232379, 252511, 252548, 253060:

- Allow to configure net.inet6.ip6.{accept_rtadv,no_radr} by the
  loader tunables as well because they have to be configured before
  interface initialization for AF_INET6.

- Allow ND6_IFF_AUTO_LINKLOCAL for IFT_BRIDGE.  An interface with IFT_BRIDGE
  is initialized with !ND6_IFF_AUTO_LINKLOCAL && !ND6_IFF_ACCEPT_RTADV
  regardless of net.inet6.ip6.accept_rtadv and net.inet6.ip6.auto_linklocal.
  To configure an autoconfigured link-local address (RFC 4862), the
  following rc.conf(5) configuration can be used:

   ifconfig_bridge0_ipv6="inet6 auto_linklocal"

- if_bridge(4) now removes IPv6 addresses on a member interface to be
  added when the parent interface or one of the existing member
  interfaces has an IPv6 address.  if_bridge(4) merges each link-local
  scope zone which the member interfaces form respectively, so it causes
  address scope violation.  Removal of the IPv6 addresses prevents it.

- if_lagg(4) now removes IPv6 addresses on a member interfaces
  unconditionally.

- Set reasonable flags to non-IPv6-capable interfaces.
MFC 253093:

Make mandoc lint happy.
MFC 253066:

Update references.
MFC 253058:

- Add missing "static" keywords.
- Add a check for ifindex to if_indextoifinfo().  It returns NULL when
  if_indextoname() fails.
MFC 245015:

Print the flags= part only when flags != 0.