Return zero rows if data source has not been set.
Bug: selection mode set assumes selected items is set.

So set the default selection mode after the selected items are
initialized.
Bug: JsonObject does not cast to generic dictionary.

Set the recipient structure to an IDictionary instead of a generic
dictionary.
Also, throw an exception if the inner async task threw one.
Aesthetic changes to make Check-in button more visible.
An abstract class for a viwe controller containing PickerViews.
An implementation of a PickerViewController for places.
Added the new classes to the project.
When the Check-in button is clicked, present a place picker view controller.

The Place Picker is working, but frame allocation is broken.