make linkId a property (id) of link

lib/router.js

@@ -13,7 +13,7 @@ define(function () {
           s += "n:" + encodeURIComponent(d.node.nodeinfo.node_id)
 
         if ("link" in d)
-          s += "l:" + encodeURIComponent(linkId(d.link))
+          s += "l:" + encodeURIComponent(d.link.id)
       }
 
       window.history.pushState(s, undefined, s)
@@ -133,7 +133,7 @@ define(function () {
       })
 
       data.graph.links.forEach( function (d) {
-        objects.links[linkId(d)] = d
+        objects.links[d.id] = d
       })
     }