[Toolkit.Graphics] Adjust swapchain size according to composition scale on SwapChainPanel control
[Toolkit.Graphics] Adds support for SwapChainPanel CompositionScale

Fixes formatting and compile conditions in SwapChainGraphicsPresenter
Merge branch 'master_integration' of https://github.com/kobush/SharpDX into pr331
[SharpDX] Fixed compilation for WinRT platform, deleted an extension that already exists in WinRT 8.1.
[Toolkit.Samples] Retargeted WinRT 8 samples to WinRT 8.1 according to the new WinRT 8.1 support.
[Toolkit.Samples] Merged SharpDXToolkitSamples.Win81.sln projects into SharpDXToolkitSamples.sln as all samples are retargeted to Windows 8.1.
[Samples.WinRT] Retargeted WinRT 8 samples to WinRT 8.1.