CollectionItemGenerator should use a populate class

[carbontwelve]

The CollectionItemGenerator should pass to the view the current item using a configurable container class. This way a user can define that they want the CollectionItemGenerator to set item equal to a defined class that gets $this->file passed to it.

[carbontwelve]

This seems to be already written in with the ViewFile class, but it's not always used.

[carbontwelve]

I think this functionality is better handled by per site extensions to plates via the League\Plates\Extension\ExtensionInterface

[carbontwelve]

The ViewFile class only seems to be passed to the view once via the pagination generator. Can its functionality not instead be provided by an plates extension?

[carbontwelve]

The reason for this is because ViewFile was added as part of #30 as a demonstration of what could happen, rather than what should happen - it should have been on it's own branch?

[carbontwelve]

So ViewFile provides blog archive and index pages helpers by wrapping a File class that it references. For example a cateogry page will have an array of ViewFile set as the variable blog_categories_items.

These helpers are not available for singular pages such as about, or even blog post pages. The question now is should these be passed a variable called $item that contains a ViewFile referencing that page - OR - should an extension to plates bring that functionality?

I am choosing to have an extension to plates that brings to the view the exact same functionality that the ViewFile class does to File items. That way each view has access to helper methods such as $this->getDate('d-m-Y') for the current file as well as to collections of files via ViewFile.