Improve validation scroll to element positions

Tidy up js
Refactor popup check in validation
Use method to check if popup is open
Refactor js form validation into its own module

Fix jshint errors
Apply new js class for validation
Refactor some of validation module into global helpers
Move parsley config into Validation module file
Move ajax callbacks into own methods for easier viewing

Remove comment

Remove session clearing
Merge pull request #116 from ministryofjustice/feature/improve-popup-validation

Improve JS validation. Popup & non-popup