Adds "All Data" filter to case list report

Addresses this ticket:
http://manage.dimagi.com/default.asp?121778#688842
It adds an "All Data" filter by modifying the `CaseListMixin` class that is subclassed by `CaseListReport`. I've examined the code of `CaseListReport`'s descendants, and none of them seem to cause conflicts with the changes made.
I'm not going to ask you to change it again, because this is getting out of hand, but I just remembered another attractive option here:

    url(r'^emwf_options/all-data/)$', api.EmwfOptionsView.as_view(all_data=True), name='emwf_options_with_all_data'),

Then the `ExpandedMobileWorkerFilter` can have a class attribute `all_data = False`, and whenever it's called from this url, that attribute will be set to `True`.  Look at the `as_view` method [here](http://ccbv.co.uk/projects/Django/1.5/django.views.generic.base/View/) for details.  [Django docs](https://docs.djangoproject.com/en/1.5/topics/class-based-views/#simple-usage-in-your-urlconf).

That'll clean up the check for it in the view too - just `if self.all_data:`