[WIP] Views hooks 

Setting up an early PR to get some feedback on views hooks.
There will be a `registerPage` hook down the line. That way the dashboard (and an extension) can register all the page hooks in a single file:

```javascript
// app/pages/customer_page.js

Balanced.registerPageHooks("customer", function(page) {
    page.registerSectionView("details", Balanced.CustomerSummarySectionView, {
            modelBinding: "controller.model"
    });
    // ......
});
```