* Provide CheckBox for selected items
Newer API's highlight the background using the "activated" state. Older
APIs need this to be implemented differently, so there are now checkboxes
on the left of the list view items to provide this functionality.
* Clean up IDE warnings
Diamond operator for generics, remove unused imports and unused method.
* Adapter class created for installed apps
Cleaned up the code to do with binding views to the adapter in this view.
Previously it made quite a few assumptions about the structure of the layout,
e.g. "layout.getParent().getParent() is a LinearLayout", which would cause
crashes if the layout changed slightly.