Add Use statement for Node class

Fixes fatal in nodeDelete().
Merge pull request #53 from weitzman/1.0

Add Use statement for Node class
Merge pull request #59 from jhedstrom/code-cleanup

Code cleanup

Signed-off-by: Jonathan Hedstrom <jhedstrom@gmail.com>

Conflicts:
	src/Drupal/Drupal.php
	src/Drupal/DrupalExtension/config/drivers/drupal.yml
Follow-up to b54ef5bc for Drupal 6 core driver.
Again followup.