Allow view options override on handler object

This pull request allows view options to be overridden in the `handler` object for a particular response. Previously, the `reply.view` method had to be used.

This is useful for specifying a different layout template for a particular route.

```js
{
  method: 'GET',
  path: '/',
  handler: {
    view: {
      template: 'homepage',
      options: {
        layout: 'specialLayoutForHomepage'
      }
    }
  }
}
```

Another use case is setting custom `runtimeOptions` for a particular route. Example:

```js
var homepageViewOptions = {
  runtimeOptions: {
    // Handlebars allows helpers to be passed to the function returned from "compile"
    helpers: {
      uppercase: function(context) {
        return context.toUpperCase();
      }
    }
  }
};

...

{
  method: 'GET',
  path: '/',
  handler: {
    view: {
      template: 'homepage',
      options: homepageViewOptions
    }
  }
}
```