Introduce WinForms support for Direct2D/DirectWrite.

[KlausLoeffelmann]

• [x] Add WinForms Control Library for Hosting D2D/DWrite supporting Controls.
• [x] Implement D2DPanel control which provides the events CreateD2DResources and D2DPaint.
• [ ] Add Samples
• [ ] Add Tests.

[JeremyKuhne]

@KlausLoeffelmann finally finished moving the DirectX stuff to function pointers as mentioned (using @tannergooding's TerraFX) https://github.com/JeremyKuhne/WInterop/commit/bc3eef5ca51c25a9aca72a40c3413502827415c4. I'll take a look at your ideas soon.

@tannergooding Figured I'd tag you as I'm now consuming your library. :) My intent with this library is to both fiddle with patterns and try to expose a "C#" friendly Windows model.