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 #4170
Closes #4490
Closes #4694
Closes #5200

Closes #5352

modules/angular1_router/build.js

@@ -6,12 +6,13 @@ var ts = require('typescript');
 var files = [
   'lifecycle_annotations_impl.ts',
   'url_parser.ts',
-  'path_recognizer.ts',
+  'route_recognizer.ts',
   'route_config_impl.ts',
   'async_route_handler.ts',
   'sync_route_handler.ts',
-  'route_recognizer.ts',
+  'component_recognizer.ts',
   'instruction.ts',
+  'path_recognizer.ts',
   'route_config_nomalizer.ts',
   'route_lifecycle_reflector.ts',
   'route_registry.ts',