EZP-22193: Make the website toolbar available from a twig pagelayout

> **Work in progress**
> **JIRA issue**: http://jira.ez.no/browse/EZP-22193
> **Required by** ezsystems/DemoBundle#52.

Implements a WebsiteToolbar controller, that uses the legacy template engine to render the web toolbar.

![ez_publish_website_toolbar_with_the_new_stack](https://f.cloud.github.com/assets/235928/2275745/3e90451e-9f2b-11e3-90da-7ff96bcb0c5c.png)

### Tasks
- [x] Make the controller only render if user has permissions (using repository checks)
- [ ] Refactor `WebsiteToolbarController:websiteToolbarAction` (move permissions checks to another service).