HoloToolkit-Unity Thanksgiving release compatible with Unity 5.4

Release notes:

1. Creating a release off of master before taking any breaking changes.
2. Contains all the contributions since HoloToolkit first launched on 30th March 2016.
3. Release works with Unity 5.4 releases.
4. This will allow developers to sync to a known point in time.
5. It will help with a better versioning story.

Upcoming releases:

1. Merge ExtensibleInputModule breaking change branch into master.
2. Move master to Unity 5.5 builds.

Thank you for your contributions and Happy Thanksgiving :)