Bug fix, Task permissions(SSF)

Bug 1: http://demo.sahanafoundation.org/eden/pr/person/93/config
Bug 2: Duplicate doesn't work -- http://demo.sahanafoundation.org/eden/admin/user/1
Bug 3: I didn't handle the deleting of tasks when the task is open in SSF, my bad.
Also, allow authenticated users to create tasks in Sunflower.
Besides, there is a better style for this kind of test:

    try:
        row = data.rows[0]
    except KeyError:
        rheader = ""
    else:
        ...build the real rheader...

    return rheader