Allow to program Endpoint link-local addresses

[aboch]

~$ docker network create nw1
c5be8936aecc7b276f22a9f3f2f441ef1c33811417d56f044ce6ac2a7a0649dc
~$ docker network create nw2
d05ddc77d6132193988dc0f01beb5fb6dbe2e5119c8595ecce4dda4373fb2e9a
~$ 
~$ docker run -d --name c0 --link-local-ip 169.254.1.1 --net nw1 alpine top
23631c5fc3349176b2dd3edc92b5a442751406edc9cacc5f1ebaf5367da1955f
~$ docker network connect --link-local-ip 169.254.2.2 --link-local-ip fe80::169:254:2:2 nw2 c0
~$ 
~$ docker exec c0 ip addr show eth0 | grep 169
    inet 169.254.1.1/16 scope global eth0
~$ docker exec c0 ip addr show eth1 | grep 169
    inet 169.254.2.2/16 scope global eth1
    inet6 fe80::169:254:2:2/64 scope link 
~$ 
~$ docker stop c0 && docker start c0
c0
c0
~$ docker exec c0 ip addr show eth0 | grep 169
    inet 169.254.1.1/16 scope global eth0
~$ docker exec c0 ip addr show eth1 | grep 169
    inet 169.254.2.2/16 scope global eth1
    inet6 fe80::169:254:2:2/64 scope link 
~$ 
~$ docker run --link-local-ip 192.168.4.4 --net nw1 alpine ifconfig
docker: Error response from daemon: invalid link local IP address: 192.168.4.4.

Signed-off-by: Alessandro Boch aboch@docker.com

[mavenugo]

LGTM