Various fixes/improvements

* Increased max height of picker view to 3 lines
* Load the top-level views from the nib instead of hardcoding them.
* Turned off autocorrect in the picker view
* Added -selectContact: method.
* Took the list of demo names out of the initializer.
* Update filteredContacts when the view appears, in case app has changed
  contacts since initializing the controller.