mollom 8.x-1.2

* Issue #2743355 by neerajsingh: Remove @file tag docblock
* Issue #2682515 by Swetha Yarla: Mollom ESLint errors
* Issue #2722215 by jojyja: Removing unused import classes in code
* Issue #2781315 by andyrigby: Fatal error in mollom_entity_update()
* Issue #2798665 by mpp: Undefined class constant TIME_OFFSET_MAX
* Issue #2603592 by eshta: Harden HTTPS checking for CAPTCHA
* Issue #2840873 by eshta: Make button name for tests dynamic based on Drupal versions
* Issue #2840873 by eshta: Fix button name in tests for Drupal 8.2
* Issue #2757937 by eshta, grasmash: composer.json does not define package type
* Issue #2683241 by snufkin: "Verification" label is not translatable
* Issue #2642800 by flocondetoile: Class of element in Mollom.php not declared in an array.
* Issue #2634932 by eshta: Add error handling for too many expected languages.