feat($compile): add custom annotations to the controller

[petebacondarwin]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  feat
• What is the current behavior? (You can also link to an open issue here)
  inconvenient
• What is the new behavior (if this is a feature change)?
  add custom annotations to the controller of component directives
• Does this PR introduce a breaking change?
  Nope
• Please check if the PR fulfills these requirements
• The commit message follows our guidelines: https://github.com/angular/angular.js/blob/master/CONTRIBUTING.md#commit-message-format
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Other information:

This means that we can access these annotations, such as
$routeConfig and $routerCanActivate without highjacking
the ng module.

[Narretz]

LGTM. What is the router doing with these annotations?

[petebacondarwin]

The router needs to extract this metadata. Previously, the annotations were added to the factory function, but this meant that we had to intercept calls to module.directive. With this change, we can use the $injector to get the controller constructor and then access the annotations that way.

[petebacondarwin]

And it allows us to get rid of a load of horrible router code. See petebacondarwin/ng1-component-router-demo@eb960ee

[petebacondarwin]

Landed with an update to the docs for the component() helper function.

[gseabrook]

I'm interested to know if I am configuring my components incorrectly as this change broke my app. My component config looks like

angular
        .module('menu')
        .component('menu', {
            controller: 'MenuController',
            templateUrl: './components/menu/menu.html',
            $canActivate: function() {
                return true; //real code omitted for brevity
            }
        });

However when "controller[key]" = val runs on line 1109 the controller variable is a string and so it fails

[petebacondarwin]

Ahah! Good catch! That is a bug.