ModelCompiler Bug Fix

Fixed a bug where the ModelCompiler would create a vertex layout with
duplicated Normal0 semantics when Assimp.Net loaded a Scene which
included both Vertex Colors and Normal Data.
[SharpDX] Clean up comments in Matrix3x2
[SharpDX] Add Matrix3x2.Transformation()
[SharpDX] Fix issue with string marshaling on Windows Phone
[Build] Use merge instead of rebase from master to master_integration
Merge branch 'master' into master_integration
[DXGI] Fix issue #103. KeyedSync.Acquire return Result. Add Result.WaitAbandoned and Result.WaitTimout. Add ResultDescriptor for common errors. Improve SharpGen to support return and check of HRESULT at the same time.
[Build] Remove SharpDoc, moved to an external github projects https://github.com/xoofx/SharpDoc . Cleanup tools, remove SharpCore/SharpDoc/SharpDocPak and integrate remaining files into SharpGen. Move specific SharpDoc styles for SharpDX into Documentation.
[Build] Remove SharpCore from SharpDXWP8.sln
[Toolkit.Graphics] Add support for IntPtr as a valid DeviceWindowHandle on Windows Desktop when creating a swapchain.
[Toolkit] Allow unloading assets by name.

* Add Unload(string assetName) to IContentManager.
* Move all asset path handling from ContentManager to FileSystemContentResolver so that the ContentManager is entirely ignorant of where an asset can be found.
[DirectWrite] Replace DirectWrite.Matrix by SharpDX.Matrix3x2
[SharpDX] Reduce duplicate lerp code and use MathUtil.Lerp() everywhere
[Toolkit] Fix compiling issue on WinRT