PHPDoc comments and some wrong class names corrected

Corrected all PHPDoc comments to match the function signature in order to make code completion in IDEs work. Works for me now in PHPStorm.

Also fixed a bug where there was an incorrect classname in an instanceof call in Builder.php and some wrong Exception class names (unnamespaced Exception was changed to \ElasticSearch\Exception)

This commit should not modify or break any functionality.