message: Delete item with Delete key (win)
diff: <KeyBinding Key="Enter" Command="{StaticResource HighlightEdit}" />
  <KeyBinding Key="Space" Command="{StaticResource HighlightContinue}" />
  <KeyBinding Key="Back" Command="{StaticResource HighlightDelete}" />
  + <KeyBinding Key="Delete" Command="{StaticResource HighlightDelete}" />
  <KeyBinding Key="Escape" Command="{StaticResource FocusTimer}" />
  <KeyBinding Key="Right" Command="{StaticResource ExpandDay}" />
  <KeyBinding Key="Left" Command="{StaticResource CollapseDay}" />
  