Revert "Open with button"

This reverts commit 923838ed39bc042b1b4a86ff6526c1ae4d497ffe.

Conflicts:
	Slideshow.v12.suo
	Slideshow/MainPage.xaml
	Slideshow/obj/Debug/MainPage.g.i.cs
	Slideshow/obj/Debug/XamlTypeInfo.g.cs