Ajax functionality for File Storage and Forums

File Uploads:
Added AJAX behaviour to add, edit and delete comments.

Forums:
Added AJAX behaviour to delete thread or reply.

Issues Solved in this pull request:
5256: http://atutor.ca/atutor/mantis/view.php?id=5256
5276: http://atutor.ca/atutor/mantis/view.php?id=5276