Issues Creating Task/Ticket from Thread

- In class.forms.php, $this->field->getClean() was null so $new was not populated and attachments were not being carried over, so we must get the fileIds directly from the form-data array
- We need to unset the form-data for attachment fields (on tasks and tickets) so that the array is empty each time we try to create a task or ticket from a thread
- We need to add files attached to threads where we are creating a task or ticket to the list of allowed files otherwise they will not carry over to new tasks/tickets (only files uploaded by this user in this session were allowed previously)