Implements Link

Fixes bradfitz/docker#9
Docker-DCO-1.1-Signed-off-by: Sasha Gerrand <github.com-dotcloud-docker@sgerrand.com> (github: sgerrand)

Docker-DCO-1.1-Signed-off-by: Sasha Gerrand <github.com@sgerrand.com> (github: sgerrand)