Changed the second parameter for disqus_help() to Drupal\Core\Routing\RouteMatchInterface.
The entity url is passed as absolute as $entity->url('canonical',array('absolute' => TRUE)).
disqus_entity_update and disqus_entity_delete checks if the disqus_comment field is present on the entity and then calls the DisqusAPI.
Removed 'version' parameter on DisqusAPI calls as api testing console on disqus.com/api/console returns response as Invalid argument with version.