[Toolkit.Game] Start refactoring internals of GamePlatform/GameWindow to have a better plugin system and support multiple sub windows system (WPF/Windows Forms on Desktop, DrawingSurface/DrawingSurfaceBackground on WP8, IFrameview/SwapchainBackgroundPanel on WinRT)
[Toolkit.Game] Start to work on desktop refactoring for GameWindow
[Toolkit.Game] Add typed GameWindowContextWinForm and update all internal class in game
[Toolkit.Game] Start refactoring internals of GamePlatform/GameWindow to have a better plugin system and support multiple sub windows system (WPF/Windows Forms on Desktop, DrawingSurface/DrawingSurfaceBackground on WP8, IFrameview/SwapchainBackgroundPanel on WinRT)
[Toolkit.Game] Start to work on desktop refactoring for GameWindow
[Toolkit.Game] Add typed GameWindowContextWinForm and update all internal class in game
Merge branch 'gamewindow_refactor' of github.com:sharpdx/SharpDX into gamewindow_refactor
[Toolkit.Game] Refactor and simplify the design of GameContext. Make it platform dependent but lighter/easier to instantiate, with a single entry point.
[Toolkit.Game] Refactor GameWindow for WinRT using CoreWindow/IFrameView
[Direct3D11] Add Device.IsSupportedFeatureLevel, remove CheckError on D3D11.CreateDevice in this case to avoid SharpDXException being catched
[Toolkit.Game] Port back support for WinRT SwapChainBackgroundPanel to new GameContext and internals GamePlatform/GameWindow.
[Toolkit.Game] Plug back WP8 DrawingBackgroungSurface support with new GameContext and internal GameWindow
[Toolkit.Game] Fix compilation errors after renaming
Merge branch 'master' into gamewindow_refactor

Conflicts:
	Samples/SharpDXToolkitSamples.sln
[WP8] Remove samples from WP8 solution
Merge branch 'master' into gamewindow_refactor