fix(router): correctly sort route matches with children by specificity

This changes the way we calculate specificity. Instead of using a number,
we use a string, so that combining specificity across parent-child instructions
becomes a matter of concatenating them

Fixes #5848

Closes #6011

modules/angular2/test/router/route_registry_spec.ts

@@ -181,6 +181,21 @@ export function main() {
              });
        }));
 
+    it('should prefer routes with high specificity over routes with children with lower specificity',
+       inject([AsyncTestCompleter], (async) => {
+         registry.config(RootHostCmp, new Route({path: '/first', component: DummyCmpA}));
+
+         // terminates to DummyCmpB
+         registry.config(RootHostCmp,
+                         new Route({path: '/:second/...', component: SingleSlashChildCmp}));
+
+         registry.recognize('/first', [])
+             .then((instruction) => {
+               expect(instruction.component.componentType).toBe(DummyCmpA);
+               async.done();
+             });
+       }));
+
     it('should match the full URL using child components', inject([AsyncTestCompleter], (async) => {
          registry.config(RootHostCmp, new Route({path: '/first/...', component: DummyParentCmp}));
 
@@ -322,6 +337,10 @@ class DummyCmpB {}
 class DefaultRouteCmp {
 }
 
+@RouteConfig([new Route({path: '/', component: DummyCmpB, name: 'ThirdCmp'})])
+class SingleSlashChildCmp {
+}
+
 
 @RouteConfig([
   new Route(

modules/angular2/test/router/router_link_spec.ts

@@ -33,8 +33,8 @@ import {
 import {DOM} from 'angular2/src/platform/dom/dom_adapter';
 import {ResolvedInstruction} from 'angular2/src/router/instruction';
 
-let dummyInstruction =
-    new ResolvedInstruction(new ComponentInstruction('detail', [], null, null, true, 0), null, {});
+let dummyInstruction = new ResolvedInstruction(
+    new ComponentInstruction('detail', [], null, null, true, '0'), null, {});
 
 export function main() {
   describe('routerLink directive', function() {