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().
Cleaning.
Add mergeCollection, diffCollection and intersectCollection functions with tests
Implement diff and intersect on Support\Collection
Rename merge, diff and intersect functions to match those on Support\Collection
Increment version.
A lot of work on failed job handling.
Return service provider instance from App::register()

Which allow 4.0 user to manually run boot()

Signed-off-by: crynobone <crynobone@gmail.com>
Refactor reused code into private function
Working on database failed job provider.
Continuing work on failed job provider.
Work on Iron releases.
Merge branch 'master' of github.com:laravel/framework
Pass the IronQueue instance to IronJob
fix phpdoc

Signed-off-by: crynobone <crynobone@gmail.com>
correct action $parameters comment to array