Added getSections() method.

I found that is impossible to get template sections from a View object
so I made it possible. This is good expecially when AJAX comes into
play.
Added renderSections() method.

I found that is impossible to get template sections from a View object
so I made it possible. This is good expecially when AJAX comes into
play.

Since the property 'section' is updated once the View has been rendered,
the correct usage is that:
```php
$view = View::make('pages');
$sections = $view->renderSections();
```
Removed old property.
Removed old code.
Restored comment on render().
Include called class name in ModelNotFoundException
Cleaning.
type check of relations
added test
Fixes issue where php path has spaces in it
Make Collection splice return new static.
Merge pull request #2743 from KaneCohen/splice-return

Make Collection splice return new static.
Fixes route in test case.
Merge pull request #2747 from sumardi/fix/route-in-testcase

[4.1] Fixes route in test case.
Allow , in wildcards
Oops
Use requestClass class.
Merge pull request #2749 from philsturgeon/patch-1

Allow , in route wildcards
Fix bug with filter method on class filters.
Merge pull request #2738 from GrahamCampbell/master

Fixes issue where php path has spaces in it