Merge commit '00410fd6' into sark-bgp-rebased

	disabled. Default: on, with automatic fallback to off when received

	capability-related error.

	<tag><label id="bgp-advertise-ipv4">advertise ipv4 <m/switch/</tag>

	Advertise IPv4 multiprotocol capability. This is not a correct behavior

	according to the strict interpretation of <rfc id="4760">, but it is

	widespread and required by some BGP implementations (Cisco and Quagga).

	This option is relevant to IPv4 mode with enabled capability

	advertisement only. Default: on.

	<tag><label id="bgp-advertise-hostname">advertise hostname <m/switch/</tag>

	Advertise hostname capability along with the hostname. Default: off.

	if (ipa_equal(b->brd, a->brd) &&

	    ipa_equal(b->opposite, a->opposite) &&

	    b->scope == a->scope &&

	    !((b->flags ^ a->flags) & IA_PEER))

	    !((b->flags ^ a->flags) & (IA_SECONDARY | IA_PEER | IA_HOST)))

	  {

	    b->flags |= IA_UPDATED;

	    return b;