To enable your project for MultiTouch, just run the following command in the Package Manager Console and all the libraries and dependencies will be added to the Visual Studio project:
PM> Install-Package MultiTouchBehaviors
Alternatively just search for the package selecting Tools->Library Package Manager->Manage NuGet Packages for Solution from Visual Studio 2012.
If you are interested in creating a NuGet package for your open-source project, register an account here in the gallery and follow the instructions described in the section “Creating and Publishing a Package“: they are very clear and contain detailed information about the process.
The package definition for MultiTouch is also available in the Source Code section on CodePlex.