refactor(angular_1_router): use directives for route targets

BREAKING CHANGE:

Previously, route configuration took a controller constructor function as the value of
`component` in a route definition:

```
$route.config([
  { route: '/', component: MyController }
])
```

Based on the name of the controller, we used to use a componentMapper service to
determine what template to pair with each controller, how to bind the instance to
the $scope.

To make the 1.x router more semantically alligned with Angular 2, we now route to a directive.
Thus a route configuration takes a normalized directive name:

```
$route.config([
  { route: '/', component: 'myDirective' }
])
```

BREAKING CHANGE:

In order to avoid name collisions, lifecycle hooks are now prefixed with `$`. Before:

```
MyController.prototype.onActivate = ...
```

After:

```
MyController.prototype.$onActivate = ...
```

Same for `$canActivate` (which now lives on the directive factory function),
`$canDeactivate`, `$canReuse`, and `$onDeactivate` hooks.

modules/angular1_router/test/directive_introspector_spec.js

@@ -0,0 +1,38 @@
+'use strict';
+
+describe('$$directiveIntrospector', function () {
+
+  var $compileProvider;
+
+  beforeEach(function() {
+    module('ng');
+    module('ngComponentRouter');
+    module(function(_$compileProvider_) {
+      $compileProvider = _$compileProvider_;
+    });
+  });
+
+  it('should call the introspector function whenever a directive factory is registered', inject(function ($$directiveIntrospector) {
+    var spy = jasmine.createSpy();
+    $$directiveIntrospector(spy);
+    function myDir(){}
+    $compileProvider.directive('myDir', myDir);
+
+    expect(spy).toHaveBeenCalledWith('myDir', myDir);
+  }));
+
+  it('should call the introspector function whenever a directive factory is registered with array annotations', inject(function ($$directiveIntrospector) {
+    var spy = jasmine.createSpy();
+    $$directiveIntrospector(spy);
+    function myDir(){}
+    $compileProvider.directive('myDir', ['foo', myDir]);
+
+    expect(spy).toHaveBeenCalledWith('myDir', myDir);
+  }));
+
+  it('should retrieve a factory based on directive name', inject(function ($$directiveIntrospector) {
+    function myDir(){}
+    $compileProvider.directive('myDir', ['foo', myDir]);
+    expect($$directiveIntrospector.getTypeByName('myDir')).toBe(myDir);
+  }));
+});