fix(router): allow generating links with numeric params

modules/angular2/src/router/path_recognizer.ts

@@ -5,8 +5,7 @@ import {
   StringWrapper,
   isPresent,
   isBlank,
-  BaseException,
-  normalizeBlank
+  BaseException
 } from 'angular2/src/facade/lang';
 import {Promise, PromiseWrapper} from 'angular2/src/facade/async';
 import {
@@ -29,6 +28,14 @@ export class Segment {
   regex: string;
 }
 
+function normalizeString(obj: any): string {
+  if (isBlank(obj)) {
+    return null;
+  } else {
+    return obj.toString();
+  }
+}
+
 class ContinuationSegment extends Segment {
   generate(params): string { return ''; }
 }
@@ -56,7 +63,7 @@ class DynamicSegment {
       throw new BaseException(
           `Route generator for '${this.name}' was not included in parameters passed.`);
     }
-    return normalizeBlank(StringMapWrapper.get(params, this.name));
+    return normalizeString(StringMapWrapper.get(params, this.name));
   }
 }
 
@@ -66,7 +73,7 @@ class StarSegment {
   constructor(public name: string) {}
 
   generate(params: StringMap<string, string>): string {
-    return normalizeBlank(StringMapWrapper.get(params, this.name));
+    return normalizeString(StringMapWrapper.get(params, this.name));
   }
 }