feat($route): when matching consider trailing slash as optional

This makes for a much more flexible route matching:

- route /foo matches /foo as well as /foo/
- route /bar/ matches /bar/ as well as /bar

Closes angular#784

src/service/route.js

@@ -246,7 +246,7 @@ function $RouteProvider(){
     function switchRouteMatcher(on, when) {
       // TODO(i): this code is convoluted and inefficient, we should construct the route matching
       //   regex only once and then reuse it
-      var regex = '^' + when.replace(/([\.\\\(\)\^\$])/g, "\\$1") + '$',
+      var regex = '^' + when.replace(/([\.\\\(\)\^\$])/g, "\\$1").replace(/\/$/, '') + '/?$',
           params = [],
           dst = {};
       forEach(when.split(/\W/), function(param) {

test/service/routeSpec.js

@@ -168,6 +168,32 @@ describe('$route', function() {
   });
 
 
+  it('should match route with and without trailing slash', function() {
+    module(function($routeProvider){
+      $routeProvider.when('/foo', {template: 'foo.html'});
+      $routeProvider.when('/bar/', {template: 'bar.html'});
+    });
+
+    inject(function($route, $location, $rootScope) {
+      $location.path('/foo');
+      $rootScope.$digest();
+      expect($route.current.template).toBe('foo.html');
+
+      $location.path('/foo/');
+      $rootScope.$digest();
+      expect($route.current.template).toBe('foo.html');
+
+      $location.path('/bar');
+      $rootScope.$digest();
+      expect($route.current.template).toBe('bar.html');
+
+      $location.path('/bar/');
+      $rootScope.$digest();
+      expect($route.current.template).toBe('bar.html');
+    });
+  });
+
+
   describe('redirection', function() {
     it('should support redirection via redirectTo property by updating $location', function() {
       module(function($routeProvider) {