Unity Editor DLL for loading motion controller models and using haptics in the Unity Editor.

This code should not be used for any purpose other than to build a DLL for the Unity Editor. The compiled DLL can be found in the MixedRealityToolkit-Unity repo, at https://github.com/Microsoft/MixedRealityToolkit-Unity/tree/master/Assets/HoloToolkit/Input/Plugins/EditorMotionController/x86 and https://github.com/Microsoft/MixedRealityToolkit-Unity/tree/master/Assets/HoloToolkit/Input/Plugins/EditorMotionController/x64.