window and Screen example: new properties; splash screen

Demonstrates the new properties, how to make a splash screen, and
how to make a standalone app with an icon.  Combined the Screen info
into this example too.

Change-Id: I5b731539b39c55327f4e5b93860a880a35835896
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
Package dialogs examples into a single executable

Introduced tabs and added the C++ boilerplate launcher.

Change-Id: Ibb49a182e3928aba5dced097d5307eb7d1f4b42d
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>