[StoreApps] Direct2D based rendering

[objorke]

From oxyplot: oxyplot/oxyplot#868

Microsoft has created Win2D WinRT wrapper for using Direct2D in Windows Store (UAP) XAML apps. We don't want to use Win2D but SharpDX (as for WPF) for rendering, but the samples might help to create a lean and performant interop layer.

References:

• https://github.com/Microsoft/Win2D
• https://github.com/sharpdx/SharpDX-Samples/tree/master/StoreApp
• https://blogs.msdn.microsoft.com/windowsappdev/2012/03/15/combining-xaml-and-directx/
• https://msdn.microsoft.com/en-us/library/windows/apps/hh825871.aspx