update to FlashMessenger view helper to allow for classes on separator
added extra test to check for separator configuration
added config test
PR #4022
Merge branch 'wryck7-hotfix/3685'
Merge pull request #4014 from BinaryKitten/FlashMessenger-Separator-Update

update to FlashMessenger view helper to allow for classes on separator
Merge branch 'hotfix/4014' into develop

Forward port #4014