Updated SP-PH-App samples to fix NuGet package reference

Updated all NuGet package references where **AppForSharePoint16WebToolkit** was present in the `packages.config` files to use the correct [AppForSharePointWebToolkit](http://www.nuget.org/packages/AppForSharePointWebToolkit) NuGet package reference instead. The incorrect references is added by the Office Dev Tools from a locally cached copy of the *AppForSharePoint16WebToolkit* package that does not exist in the public [NuGet Package registry](http://www.nuget.org/packages). This causes an issue when cloning the project from source control and doing a local "NuGet Package Restore".

Also cleared our any values for the **ClientID** or **ClientSecret** in the `web.config` files.