add DOVE extensions for iproute2

This patch adds a new flag to iproute2 for vxlan devices to enable
DOVE features. It also adds support for L2 and L3 switch lookup miss
netlink messages to "ip monitor".

Changes since v2: fix merge conflict
Changes since v1:
	- split "dove" flag into separate feature flags:
		- "proxy" for ARP reduction
		- "rsc" for route short circuiting
		- "l2miss" for L2 switch miss notifications
		- "l3miss" for L3 switch miss notifications

Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
diff --git a/ip/ipmonitor.c b/ip/ipmonitor.c
index d87e58f..d971623 100644
--- a/ip/ipmonitor.c
+++ b/ip/ipmonitor.c
@@ -67,7 +67,8 @@
 		print_addrlabel(who, n, arg);
 		return 0;
 	}
-	if (n->nlmsg_type == RTM_NEWNEIGH || n->nlmsg_type == RTM_DELNEIGH) {
+	if (n->nlmsg_type == RTM_NEWNEIGH || n->nlmsg_type == RTM_DELNEIGH ||
+	    n->nlmsg_type == RTM_GETNEIGH) {
 		if (prefix_banner)
 			fprintf(fp, "[NEIGH]");
 		print_neigh(who, n, arg);