Bug fix, Task permissions(SSF)

Bug 1: http://demo.sahanafoundation.org/eden/pr/person/93/config
Bug 2: Duplicate doesn't work -- http://127.0.0.1:8000/eden/admin/user/1/
Bug 3: I didn't handle the deleting of tasks when it's opened, my bad.
Also, allow authenticated users to create tasks in Sunflower.