feature #10699 [DomCrawler] Added support for slicing nodes (Berat Doğan, beratdogan)

This PR was squashed before being merged into the 2.6-dev branch (closes #10699).

Discussion
----------

[DomCrawler] Added support for slicing nodes

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT

There are no easy way to slice nodes in specific range. I created a method using \LimitIterator. Works fine for me.

An example using is:
```php
     $crawler->filter('h1')->slice(5, 10)->each(function ($node, $i) {
         return $node->text();
     });

Commits
-------

1181bdc [DomCrawler] Added support for slicing nodes

src/Symfony/Component/DomCrawler/Crawler.php

@@ -341,6 +341,19 @@ class Crawler extends \SplObjectStorage
         return $data;
     }
 
+    /**
+     * Slices the list of nodes by $offset and $length.
+     *
+     * @param int $offset
+     * @param int $length
+     *
+     * @return Crawler A Crawler instance with the sliced nodes
+     */
+    public function slice($offset = 0, $length = -1)
+    {
+        return new static(iterator_to_array(new \LimitIterator($this, $offset, $length)), $this->uri);
+    }
+
     /**
      * Reduces the list of nodes by calling an anonymous function.
      *

src/Symfony/Component/DomCrawler/Tests/CrawlerTest.php

@@ -313,6 +313,16 @@ EOF
         $this->assertEquals(array('0-One', '1-Two', '2-Three'), $data, '->each() executes an anonymous function on each node of the list');
     }
 
+    public function testSlice()
+    {
+        $crawler = $this->createTestCrawler()->filterXPath('//ul[1]/li');
+        $this->assertNotSame($crawler->slice(), $crawler, '->slice() returns a new instance of a crawler');
+        $this->assertInstanceOf('Symfony\\Component\\DomCrawler\\Crawler', $crawler->slice(), '->slice() returns a new instance of a crawler');
+
+        $this->assertCount(3, $crawler->slice(), '->slice() does not slice the nodes in the list if any param is entered');
+        $this->assertCount(1, $crawler->slice(1, 1), '->slice() slices the nodes in the list');
+    }
+
     public function testReduce()
     {
         $crawler = $this->createTestCrawler()->filterXPath('//ul[1]/li');