refactor(router): improve recognition and generation pipeline

This is a big change. @matsko also deserves much of the credit for the implementation.

Previously, `ComponentInstruction`s held all the state for async components.
Now, we introduce several subclasses for `Instruction` to describe each type of navigation.

BREAKING CHANGE:

Redirects now use the Link DSL syntax. Before:

```
@RouteConfig([
	{ path: '/foo', redirectTo: '/bar' },
	{ path: '/bar', component: BarCmp }
])
```

After:

```
@RouteConfig([
	{ path: '/foo', redirectTo: ['Bar'] },
	{ path: '/bar', component: BarCmp, name: 'Bar' }
])
```

BREAKING CHANGE:

This also introduces `useAsDefault` in the RouteConfig, which makes cases like lazy-loading
and encapsulating large routes with sub-routes easier.

Previously, you could use `redirectTo` like this to expand a URL like `/tab` to `/tab/posts`:

@RouteConfig([
	{ path: '/tab', redirectTo: '/tab/users' }
	{ path: '/tab', component: TabsCmp, name: 'Tab' }
])
AppCmp { ... }

Now the recommended way to handle this is case is to use `useAsDefault` like so:

```
@RouteConfig([
	{ path: '/tab', component: TabsCmp, name: 'Tab' }
])
AppCmp { ... }

@RouteConfig([
	{ path: '/posts', component: PostsCmp, useAsDefault: true, name: 'Posts' },
	{ path: '/users', component: UsersCmp, name: 'Users' }
])
TabsCmp { ... }
```

In the above example, you can write just `['/Tab']` and the route `Users` is automatically selected as a child route.

Closes #4728
Closes #4228
Closes #4170
Closes #4490
Closes #4694
Closes #5200

Closes #5475

modules/angular2/test/router/integration/util.ts

@@ -0,0 +1,133 @@
+import {provide, Provider, Component, View} from 'angular2/core';
+import {Type, isBlank} from 'angular2/src/facade/lang';
+import {BaseException} from 'angular2/src/facade/exceptions';
+
+import {
+  RootTestComponent,
+  AsyncTestCompleter,
+  TestComponentBuilder,
+  beforeEach,
+  ddescribe,
+  xdescribe,
+  describe,
+  el,
+  inject,
+  beforeEachProviders,
+  it,
+  xit
+} from 'angular2/testing_internal';
+
+import {RootRouter} from 'angular2/src/router/router';
+import {Router, ROUTER_DIRECTIVES, ROUTER_PRIMARY_COMPONENT} from 'angular2/router';
+
+import {SpyLocation} from 'angular2/src/mock/location_mock';
+import {Location} from 'angular2/src/router/location';
+import {RouteRegistry} from 'angular2/src/router/route_registry';
+import {DirectiveResolver} from 'angular2/src/core/linker/directive_resolver';
+import {DOM} from 'angular2/src/platform/dom/dom_adapter';
+export {ComponentFixture} from 'angular2/testing_internal';
+
+
+/**
+ * Router test helpers and fixtures
+ */
+
+@Component({
+  selector: 'root-comp',
+  template: `<router-outlet></router-outlet>`,
+  directives: [ROUTER_DIRECTIVES]
+})
+export class RootCmp {
+  name: string;
+}
+
+export function compile(tcb: TestComponentBuilder,
+                        template: string = "<router-outlet></router-outlet>") {
+  return tcb.overrideTemplate(RootCmp, ('<div>' + template + '</div>')).createAsync(RootCmp);
+}
+
+export var TEST_ROUTER_PROVIDERS = [
+  RouteRegistry,
+  DirectiveResolver,
+  provide(Location, {useClass: SpyLocation}),
+  provide(ROUTER_PRIMARY_COMPONENT, {useValue: RootCmp}),
+  provide(Router, {useClass: RootRouter})
+];
+
+export function clickOnElement(anchorEl) {
+  var dispatchedEvent = DOM.createMouseEvent('click');
+  DOM.dispatchEvent(anchorEl, dispatchedEvent);
+  return dispatchedEvent;
+}
+
+export function getHref(elt) {
+  return DOM.getAttribute(elt, 'href');
+}
+
+
+/**
+ * Router integration suite DSL
+ */
+
+var specNameBuilder = [];
+
+// we add the specs themselves onto this map
+export var specs = {};
+
+export function describeRouter(description: string, fn: Function, exclusive = false): void {
+  var specName = descriptionToSpecName(description);
+  specNameBuilder.push(specName);
+  describe(description, fn);
+  specNameBuilder.pop();
+}
+
+export function ddescribeRouter(description: string, fn: Function, exclusive = false): void {
+  describeRouter(description, fn, true);
+}
+
+export function describeWithAndWithout(description: string, fn: Function): void {
+  // the "without" case is usually simpler, so we opt to run this spec first
+  describeWithout(description, fn);
+  describeWith(description, fn);
+}
+
+export function describeWith(description: string, fn: Function): void {
+  var specName = 'with ' + description;
+  specNameBuilder.push(specName);
+  describe(specName, fn);
+  specNameBuilder.pop();
+}
+
+export function describeWithout(description: string, fn: Function): void {
+  var specName = 'without ' + description;
+  specNameBuilder.push(specName);
+  describe(specName, fn);
+  specNameBuilder.pop();
+}
+
+function descriptionToSpecName(description: string): string {
+  return spaceCaseToCamelCase(description);
+}
+
+// this helper looks up the suite registered from the "impl" folder in this directory
+export function itShouldRoute() {
+  var specSuiteName = spaceCaseToCamelCase(specNameBuilder.join(' '));
+
+  var spec = specs[specSuiteName];
+  if (isBlank(spec)) {
+    throw new BaseException(`Router integration spec suite "${specSuiteName}" was not found.`);
+  } else {
+    // todo: remove spec from map, throw if there are extra left over??
+    spec();
+  }
+}
+
+function spaceCaseToCamelCase(str: string): string {
+  var words = str.split(' ');
+  var first = words.shift();
+  return first + words.map(title).join('');
+}
+
+function title(str: string): string {
+  return str[0].toUpperCase() + str.substring(1);
+}