* Only start ScrollGesture when left click pressed, also `GetCurrentPoint(null)` behaves the same as root visual
* Allow right-click pen to select items on press
* Add context menus to even items on ListBox page for testing
* Avoid global static in UpdateSelectionFromPointerEvent
* Revert "Avoid global static in UpdateSelectionFromPointerEvent"
This reverts commit 2562d73e83.
* Add comment to UpdateSelectionFromPointerEvent
* Use fully mocked rendering for list box test
* Add pen selection tests
* TouchTestHelper should use correct inputs
- Don't make selection follow focus
- Move all keyboard interaction into `ListBox`
- Move all pointer interaction into `ListBoxItem`
- Added `ItemsControl.ItemsControlFromItemContaner` as in WPF
A lot still broken, in particular virtualization is completely removed.`ItemsPresenter` now no longer has an `Items` or `ItemTemplate` property; it detects when it's hosted in an `ItemsControl`. `IItemsPresenter` interface removed.
...during ApplyTemplate. This was so that ItemsControls could their find
ItemsPresenters nested in other templated controls. Instead use
IItemsPresenterHost to make the presenter register itself with its
TemplatedParent.