changes in Facebook.Client for Windows Phone 8

Back in the day, a contractor wrote an app us with the following Facebook bits:

<package id="Facebook" version="6.4.2" targetFramework="wp80" />
<package id="Facebook.Client" version="0.7.0-alpha" targetFramework="wp80" />

The current versions of these libs are:

<package id="Facebook" version="7.0.6" targetFramework="wp80" />
<package id="Facebook.Client" version="1.0.3" targetFramework="wp80" />

However, upgrading to these versions leads to a couple of classes (at least FacebookSessionClient and FacebookSession) missing.

Have these classes been simply renamed or has there been a major re-work of these libraries?

The reason I ask is that certain Facebook APIs will stop working at the end of the month and I want to update the code to use the new APIs (or remove deprecated features).

If there has been a major re-work, is there a migration guide that I can look at before I start?