[DomCrawler] Added more tests for the XPath filtering

This will ensure we don't introduce regressions again when fixing #10206.
[DomCrawler] Fixed filterXPath() chaining
Fixed the XPath filtering to have the same behavior than Symfony 2.4
Merge branch '2.3' into 2.4

* 2.3:
  Fixed the XPath filtering to have the same behavior than Symfony 2.4
  [DomCrawler] Fixed filterXPath() chaining
  [DomCrawler] Added more tests for the XPath filtering
  [HttpKernel] fixed file uploads in functional tests when no file was selected
  Fixed test cases failing when the Intl extension is not installed
  Fixed the Travis build to avoid exiting too early

Conflicts:
	src/Symfony/Component/DomCrawler/Crawler.php
	src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php